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Lotgering, F. K., P. C. Struijk, M. B. van Doorn, and H. C. Wallenburg. "Errors in predicting maximal oxygen consumption in pregnant women." Journal of Applied Physiology 72, no. 2 (February 1, 1992): 562–67. http://dx.doi.org/10.1152/jappl.1992.72.2.562.
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This study was designed to determine the accuracy of estimated values of maximal heart rate (HRmax) and oxygen consumption (VO2) during pregnancy. We measured HR and maximal VO2 (VO2max) at rest and during cycle (CE) and treadmill exercise (TE) tests with rapidly increasing exercise intensities during gestation and after delivery. Pregnancy was found to affect the linear relationship of HR and %VO2max so that the intercept increases with advancing gestation and the slope decreases. Estimated maximal HR (HRmax, est), 220 - age (yr) x beats/min, overestimated measured HRmax by 8% (CE) and 5% (TE). For VO2max estimated by Astrand's nomogram (VO2max, est1) and by linear extrapolation of submaximal values of HR and VO2 to HRmax, est (VO2max, est2), individual errors were large (SD 17–28%). Mean VO2max, est1 overestimated measured VO2max by 20% during CE but not during TE (-2%) and elicited the erroneous impression that VO2max decreases during CE in pregnancy. Mean VO2max, est2 values were not significantly different from measured VO2max values. This apparent accuracy resulted from two opposing errors: 1) HRmax, est overestimated HRmax, and 2) above 70% VO2max the slope of the HR-%VO2max relationship was significantly reduced. Therefore neither method to estimate VO2max can replace the measurement of VO2max.
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Garland, T., and A. F. Bennett. "Quantitative genetics of maximal oxygen consumption in a garter snake." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 259, no. 5 (November 1, 1990): R986—R992. http://dx.doi.org/10.1152/ajpregu.1990.259.5.r986.
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Broad-sense heritabilities and genetic correlations of maximal oxygen consumption (VO2max), blood hemoglobin levels, and ventricle mass were estimated in a natural population of snakes. Traits were measured for six or fewer presumed full-sibling offspring from each of 45 wild-caught gravid garter snakes (Thamnophis sirtalis). VO2max was highly reproducible between replicate trial days (r = 0.88). In an attempt to reduce maternal effects, correlations of each character with body mass, snout-vent length, age at testing, litter size, dam mass, and dam snout-vent length were removed by computing residuals from multiple-regression equations. These residuals were used in subsequent genetic analyses. Approximate coefficients of variation of residuals were 16% for VO2max, 19% for hemoglobin level, and 13% for ventricle mass. Broad-sense heritabilities were highly significant for all characters [P less than 0.0001; VO2max heritability (h2) = 0.88; hemoglobin level h2 = 0.63; ventricle mass h2 = 0.41], suggesting that they could respond genetically to selection. Phenotypic correlations (rP) among residual characters were significant only between VO2max and ventricle mass (rP = +0.27). VO2max and ventricle mass exhibited a significant (broad-sense) genetic correlation of +0.64; this might facilitate the correlated evolution of these two traits in response to natural or artificial selection. Ventricle mass and hemoglobin level showed a significant environmental correlation of +0.43. Treadmill endurance crawling time (Evolution 42: 335-350, 1988) showed a weak but significantly positive rP with VO2max (rP = +0.17).
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Jones, M. T., R. E. Rawson, and D. Robertshaw. "Determination of maximal oxygen consumption in exercising pregnant sheep." Journal of Applied Physiology 73, no. 1 (July 1, 1992): 234–39. http://dx.doi.org/10.1152/jappl.1992.73.1.234.
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Previous work with pregnant ewes has shown that acute bouts of exercise may cause changes in plasma hormone concentrations, blood flow distribution, and maternal and fetal temperatures. However, most of these studies do not quantify the chosen exercise intensity through measurement of oxygen consumption (VO2). Therefore the purpose of this study was to statistically model the VO2 response of pregnant sheep to treadmill (TM) exercise to determine the exercise intensities (% maximal VO2) of previous studies. Ewes with either single (n = 9) or twin (n = 5) fetuses were studied from 100 to 130 days of gestation. After 1–2 wk of TM habituation, maximal VO2 (VO2max) was determined by measurements of VO2 (open flow-through method) and blood lactate concentration. VO2 was measured as a function of TM incline (0, 3, 5, and 7 degree) and speed (0.8–3.4 m/s). VO2max averaged 57 +/- 7 (SD) ml.min-1.kg-1, and peak lactate concentration during exercise averaged 22 +/- 2 mmol/l. The relationship between VO2 (ml.min-1.kg-1) and incline (INC) and speed (SP) [VO2 = 0.70(INC) + 13.95(SP) + 1.07(INC x SP) - 1.18] was linear (r2 = 0.94). Our findings suggest that most previous research used exercise intensities less than 60% VO2max and indicate the need for further research that examines the effect of exercise during pregnancy at levels greater than 60% VO2max.
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Rivera, A. M., A. E. Pels, S. P. Sady, M. A. Sady, E. M. Cullinane, and P. D. Thompson. "Physiological factors associated with the lower maximal oxygen consumption of master runners." Journal of Applied Physiology 66, no. 2 (February 1, 1989): 949–54. http://dx.doi.org/10.1152/jappl.1989.66.2.949.
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We examined the hemodynamic factors associated with the lower maximal O2 consumption (VO2max) in older formerly elite distance runners. Heart rate and VO2 were measured during submaximal and maximal treadmill exercise in 11 master [66 +/- 8 (SD) yr] and 11 young (32 +/- 5 yr) male runners. Cardiac output was determined using acetylene rebreathing at 30, 50, 70, and 85% VO2max. Maximal cardiac output was estimated using submaximal stroke volume and maximal heart rate. VO2max was 36% lower in master runners (45.0 +/- 6.9 vs. 70.4 +/- 8.0 ml.kg-1.min-1, P less than or equal to 0.05), because of both a lower maximal cardiac output (18.2 +/- 3.5 vs. 25.4 +/- 1.7 l.min-1) and arteriovenous O2 difference (16.6 +/- 1.6 vs. 18.7 +/- 1.4 ml O2.100 ml blood-1, P less than or equal to 0.05). Reduced maximal heart rate (154.4 +/- 17.4 vs. 185 +/- 5.8 beats.min-1) and stroke volume (117.1 +/- 16.1 vs. 137.2 +/- 8.7 ml.beat-1) contributed to the lower cardiac output in the older athletes (P less than or equal 0.05). These data indicate that VO2max is lower in master runners because of a diminished capacity to deliver and extract O2 during exercise.
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Musch, T. I., G. C. Haidet, G. A. Ordway, J. C. Longhurst, and J. H. Mitchell. "Dynamic exercise training in foxhounds. I. Oxygen consumption and hemodynamic responses." Journal of Applied Physiology 59, no. 1 (July 1, 1985): 183–89. http://dx.doi.org/10.1152/jappl.1985.59.1.183.
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Ten foxhounds were studied during maximal and submaximal exercise on a motor-driven treadmill before and after 8–12 wk of training. Training consisted of working at 80% of maximal heart rate 1 h/day, 5 days/wk. Maximal O2 consumption (VO2max) increased 28% from 113.7 +/- 5.5 to 146.1 +/- 5.4 ml O2 X min-1 X kg-1, pre- to posttraining. This increase in VO2max was due primarily to a 27% increase in maximal cardiac output, since maximal arteriovenous O2 difference increased only 4% above pretraining values. Mean arterial pressure during maximal exercise did not change from pre- to posttraining, with the result that calculated systemic vascular resistance (SVR) decreased 20%. There were no training-induced changes in O2 consumption, cardiac output, arteriovenous O2 difference, mean arterial pressure, or SVR at any level of submaximal exercise. However, if post- and pretraining values are compared, heart rate was lower and stroke volume was greater at any level of submaximal exercise. Venous lactate concentrations during a given level of submaximal exercise were significantly lower during posttraining compared with pretraining, but venous lactate concentrations during maximal exercise did not change as a result of exercise training. These results indicate that a program of endurance training will produce a significant increase in VO2max in the foxhound. This increase in VO2max is similar to that reported previously for humans and rats but is derived primarily from central (stroke volume) changes rather than a combination of central and peripheral (O2 extraction) changes.
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Yuktasir, Bekir. "Warm-up: A case study on maximal oxygen consumption as it relates to acute stretching." Journal of Human Kinetics 19, no. 1 (January 1, 2008): 165–76. http://dx.doi.org/10.2478/v10078-008-0013-y.
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Warm-up: A case study on maximal oxygen consumption as it relates to acute stretchingThe aim of this study was to determine the acute effects of static and Proprioceptive Neuromuscular Facilitation (PNF) stretches on maximal oxygen consumption (VO2max). Ten physically active men (mean ± SD, 23.80 ± 1.54 years, 70.60 ± 9.70 kg, 1.74.60 ± 5.23 m), who were healthy students volunteered to take part in the study. The participants were subjected to Static and PNF stretching exercises. After the interventions, the Bruce treadmill protocol was applied to measure VO2max values. The expired gases were collected and analyzed continuously using the Cortex Metalyzer II. Analysis of variance showed significant main effects for interventions (F(2,18)=10.74, p<.05) on VO2max. The main result of this study showed that both static and PNF stretching exercises improved VO2max values.
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Pelletier, Denis M., Guillaume Lacerte, and Eric D. B. Goulet. "Effects of Quercetin Supplementation on Endurance Performance and Maximal Oxygen Consumption: A Meta-Analysis." International Journal of Sport Nutrition and Exercise Metabolism 23, no. 1 (February 2013): 73–82. http://dx.doi.org/10.1123/ijsnem.23.1.73.
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Lately, the effect of quercetin supplementation (QS) on endurance performance (EP) and maximal oxygen consumption (VO2max) has been receiving much scientific and media attention. Therefore, a meta-analysis was performed to determine QS’s ergogenic value on these variables. Studies were located with database searches (PubMed and SPORTDiscus) and cross-referencing. Outcomes represent mean percentage changes in EP (measured via power output) and VO2max between QS and placebo. Random-effects model meta-regression, mixed-effects model analog to the ANOVA, random-effects weighted mean effect summary, and magnitudebased inferences analyses were used to delineate the effects of QS. Seven research articles (representing 288 subjects) were included, producing 4 VO2max and 10 EP effect estimates. Mean QS daily intake and duration were, respectively, 960 ± 127 mg and 26 ± 24 d for the EP outcome and 1,000 ± 0 mg and 8 ± 23 d for the VO2max outcome. EP was assessed during exercise with a mean duration of 79 ± 82 min. Overall, QS improved EP by 0.74% (95% CI: 0.10–1.39, p = .02) compared with placebo. However, only in untrained individuals (0.83% ± 0.78%, p = .02) did QS significantly improve EP (trained individuals: 0.09% ± 2.15%, p = .92). There was no relationship between QS duration and EP (p = .69). Overall, QS increased VO2max by 1.94% (95% CI: 0.30–3.59, p = .02). Magnitude-based inferences suggest that the effect of QS on EP and VO2max is likely to be trivial for both trained and untrained individuals. In conclusion, this meta-analysis indicates that QS is unlikely to prove ergogenic for aerobic-oriented exercises in trained and untrained individuals.
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Taylor, Katrina, Jeffrey Seegmiller, and Chantal A. Vella. "The Decremental Protocol as an Alternative Protocol to Measure Maximal Oxygen Consumption in Athletes." International Journal of Sports Physiology and Performance 11, no. 8 (November 2016): 1094–99. http://dx.doi.org/10.1123/ijspp.2015-0488.
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Purpose:To determine whether a decremental protocol could elicit a higher maximal oxygen consumption (VO2max) than an incremental protocol in trained participants. A secondary aim was to examine whether cardiac-output (Q) and stroke-volume (SV) responses differed between decremental and incremental protocols in this sample. Methods:Nineteen runners/triathletes were randomized to either the decremental or incremental group. All participants completed an initial incremental VO2max test on a treadmill, followed by a verification phase. The incremental group completed 2 further incremental tests. The decremental group completed a second VO2max test using the decremental protocol, based on their verification phase. The decremental group then completed a final incremental test. During each test, VO2, ventilation, and heart rate were measured, and cardiac variables were estimated with thoracic bioimpedance. Repeated-measures analysis of variance was conducted with an alpha level set at .05. Results:There were no significant main effects for group (P = .37) or interaction (P = .10) over time (P = .45). VO2max was similar between the incremental (57.29 ± 8.94 mL · kg–1 · min–1) and decremental (60.82 ± 8.49 mL · kg–1 · min–1) groups over time. Furthermore, Q and SV were similar between the incremental (Q 22.72 ± 5.85 L/min, SV 119.64 ± 33.02 mL/beat) and decremental groups (Q 20.36 ± 4.59 L/min, SV 109.03 ± 24.27 mL/beat) across all 3 trials. Conclusions:The findings suggest that the decremental protocol does not elicit higher VO2max than an incremental protocol but may be used as an alternative protocol to measure VO2max in runners and triathletes.
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Jones, J. H., K. E. Longworth, A. Lindholm, K. E. Conley, R. H. Karas, S. R. Kayar, and C. R. Taylor. "Oxygen transport during exercise in large mammals. I. Adaptive variation in oxygen demand." Journal of Applied Physiology 67, no. 2 (August 1, 1989): 862–70. http://dx.doi.org/10.1152/jappl.1989.67.2.862.
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This study investigated mechanisms used by horses and steers to increase O2 uptake and delivery (VO2) from resting to maximal rates and identified the mechanisms that enable horses to achieve higher maximal rates of O2 consumption (VO2max) than steers. VO2 and circulatory variables were measured while Standardbred trotting horses and steers (450-kg body mass) stood quietly and ran on a treadmill at speeds up to those eliciting VO2max. As VO2 increased in both species, heart rate and circulating hemoglobin (Hb) concentration increased, thereby increasing O2 delivery by the circulation, while cardiac stroke volume remained unchanged. At VO2max arterial PCO2 increased from its resting value in horses but was unchanged in steers, and arterial PO2 decreased in both species. Although the horses hypoventilated and were hypoxemic at VO2max, no significant decrease in arterial Hb saturation occurred. VO2max of the horses was 2.6 times higher than that of the steers and was associated with a 100% larger cardiac output, 100% larger stroke volume, and 40% higher Hb concentration, whereas heart rates at VO2max were identical in the two species. The higher cardiac output of the horses at VO2max resulted from a 1.2-fold higher mean arterial pressure and 1.6-fold lower peripheral tissue resistance (associated with a larger skeletal muscle capillary bed). Both the magnitude of the difference in VO2max between horses and steers and the mechanisms used to achieve it are the same as observed in smaller pairs of mammalian species with large variation in aerobic capacity.
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HOSSINI, M. Khorshidi, A. VALIZADEH, L. BOLBOLI, and A. MEAMARBASHI. "Evaluation and Development of Non-Exercise Prediction Models of Maximal Oxygen Consumption in Azerbaijan-Iranian Young Men." Asian Journal of Physical Education & Recreation 18, no. 1 (June 1, 2012): 50–57. http://dx.doi.org/10.24112/ajper.181861.
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LANGUAGE NOTE | Document text in English; abstract also in Chinese.
The purpose of this study was to develop a regression equation to predict maximal oxygen consumption (VO2max) based on non-exercise (N-EX) data and to investigate the validity of these equations in healthy young men. One hundred healthy men (age: 18-26 years) were randomly separated in two equal groups (n=50). All participants, successfully completed a maximal graded exercise test (GXT) to assess VO2max (Mean = 45.56 ml × kg-1 × min-1, SD = 4.14). The N-EX data collected just before the maximal GXT including participants’ age; body mass index (BMI); perceived functional ability (PFA) to walk, jog, or run given distances; and current physical activity (PA-R) level. Methodological differences among these methods (new equation and GXT in the validation group) were analyzed with Bland-Altman (1986) method. A good correlation coefficients were observed between VO2max and body mass index (BMI) (r = -0.50), PFA (r = 0.71) and PA-R (r = 0.70) in the development group (p< 0.05). Multiple linear regression generated the following N-EX prediction equation: VO2max (ml × kg-1 × min-1) = 47.718 – (0.38516 × BMI) + (0.8541 × PA-R) + (0.2539 × PFA). When new VO2max prediction equation were applied to the validation group, high agreement were also observed between measured VO2max by GXT and predicted VO2max (mean±SD: 0.58±2.53) (p< 0.05). This study provided an N-EX regression model that yields relatively accurate results and it is a convenient way to predict VO2max in Azerbaijan–Iranian young men with a similar cardiorespiratory fitness level. Authors recommend further studies to elucidate generality of the new equation.
本研究旨在計算預測年青人最大攝氧量的公式，邀請了100位健康男士，分成兩組進行測驗。結果顯示，推算最大攝氧量的公式如下: VO2max (ml × kg-1 × min-1) = 47.718 – (0.38516 × BMI) + (0.8541 × PA-R) + (0.2539 × PFA) 。
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Yusuf, Mohd, R. B. Kamal, Manish Bajpai, Kavita Chawla, and Piyush Saxena. "A comparative study of maximal oxygen consumption (VO2max) determined by two sub-maximal exercise tests." Indian Journal of Clinical Anatomy and Physiology 5, no. 4 (November 15, 2018): 515–18. http://dx.doi.org/10.18231/2394-2126.2018.0118.
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Esco, Michael R., Ronald L. Snarr, Andrew Flatt, Matthew Leatherwood, and Adam Whittaker. "Tracking Changes in Maximal Oxygen Consumption with the Heart Rate Index in Female Collegiate Soccer Players." Journal of Human Kinetics 42, no. 1 (October 1, 2014): 103–11. http://dx.doi.org/10.2478/hukin-2014-0065.
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Abstract The purpose of this study was to determine if the HRindex Method (VO2max = [6 x HRindex - 5] x 3.5, where HRindex = HRmax/HRrest) was accurate for tracking changes in VO2max following 8-weeks of endurance training among collegiate female soccer players. Predicted VO2max via the HRindex Method and observed VO2max from a maximal exercise test on a treadmill were determined for a group of female soccer athletes (n = 15) before and following an 8-week endurance training protocol. The predicted (pVO2max) and observed (aVO2max) values were compared at baseline and within 1-week post-training. Change values (i.e., the difference between pre to post) for each variable were also determined and compared. There was a significant difference between aVO2max before (43.2 ± 2.8 ml.kg.min-1) and following (46.2 ± 2.1 ml.kg.min-1) the 8-week training program (p < 0.05). However, pVO2max did not significantly change following training (pre = 43.4 ± 4.6 ml.kg.min-1, post = 42.9 ± 4.1 ml.kg.min-1, p = 0.53). Furthermore, the correlation between the change in aVO2max and the change in pVO2max was trivial and non-significant (r = 0.30, p = 0.28). The HRindex Method does not appear to be suitable for predicting changes in VO2max following 8-weeks of endurance training in female collegiate soccer players
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Mikalački, Milena, Nebojša Čokorilo, and Pedro Jesús Ruiz-Montero. "The effects of a pilates-aerobic program on maximum exercise capacity of adult women." Revista Brasileira de Medicina do Esporte 23, no. 3 (May 2017): 246–49. http://dx.doi.org/10.1590/1517-869220172303156004.
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ABSTRACT Introduction: Physical exercise such as the Pilates method offers clinical benefits on the aging process. Likewise, physiologic parameters may be improved through aerobic exercise. Methods: In order to compare the differences of a Pilates-Aerobic intervention program on physiologic parameters such as the maximum heart rate (HRmax), relative maximal oxygen consumption (relative VO2max) and absolute (absolute VOmax), maximum heart rate during maximal oxygen consumption (VO2max-HRmax), maximum minute volume (VE) and forced vital capacity (FVC), a total of 64 adult women (active group = 48.1 ± 6.7 years; control group = 47.2 ± 7.4 years) participated in the study. The physiological parameters, the maximal speed and total duration of test were measured by maximum exercise capacity testing through Bruce protocol. The HRmax was calculated by a cardio-ergometric software. Pulmonary function tests, maximal speed and total time during the physical test were performed in a treadmill (Medisoft, model 870c). Likewise, the spirometry analyzed the impact on oxygen uptake parameters, including FVC and VE. Results: The VO2max (relative and absolute), VE (all, P<0.001), VO2max-HRmax (P<0.05) and maximal speed of treadmill test (P<0.001) showed significant difference in the active group after a physical exercise interventional program. Conclusion: The present study indicates that the Pilates exercises through a continuous training program might significantly improve the cardiovascular system. Hence, mixing strength and aerobic exercises into a training program is considered the optimal mechanism for healthy aging.
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Carriker, Colin R., Christine M. Mermier, Trisha A. VanDusseldorp, Kelly E. Johnson, Nicholas M. Beltz, Roger A. Vaughan, James J. McCormick, Nathan H. Cole, Christopher C. Witt, and Ann L. Gibson. "Effect of Acute Dietary Nitrate Consumption on Oxygen Consumption During Submaximal Exercise in Hypobaric Hypoxia." International Journal of Sport Nutrition and Exercise Metabolism 26, no. 4 (August 2016): 315–22. http://dx.doi.org/10.1123/ijsnem.2015-0144.
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Reduced partial pressure of oxygen impairs exercise performance at altitude. Acute nitrate supplementation, at sea level, may reduce oxygen cost during submaximal exercise in hypobaric hypoxia. Therefore, we investigated the metabolic response during exercise at altitude following acute nitrate consumption. Ten well-trained (61.0 ± 7.4 ml/kg/min) males (age 28 ± 7 yr) completed 3 experimental trials (T1, T2, T3). T1 included baseline demographics, a maximal aerobic capacity test (VO2max) and five submaximal intensity cycling determination bouts at an elevation of 1600 m. A 4-day dietary washout, minimizing consumption of nitrate-rich foods, preceded T2 and T3. In a randomized, double-blind, placebo-controlled, crossover fashion, subjects consumed either a nitrate-depleted beetroot juice (PL) or ~12.8 mmol nitrate rich (NR) beverage 2.5 hr before T2 and T3. Exercise at 3500 m (T2 and T3) via hypobaric hypoxia consisted of a 5-min warm-up (25% of normobaric (VO2max) and four 5-min cycling bouts (40, 50, 60, 70% of normobaric VO2max) each separated by a 4-min rest period. Cycling RPM and watts for each submaximal bout during T2 and T3 were determined during T1. Preexercise plasma nitrite was elevated following NR consumption compared with PL (1.4 ± 1.2 and 0.7 ± 0.3 uM respectively; p < .05). There was no difference in oxygen consumption (−0.5 ± 1.8, 0.1 ± 1.7, 0.7 ± 2.1, and 1.0 ± 3.0 ml/kg/min) at any intensity (40, 50, 60, 70% of VO2max), respectively) between NR and PL. Further, respiratory exchange ratio, oxygen saturation, heart rate and rating of perceived exertion were not different at any submaximal intensity between NR and PL either. Blood lactate, however, was reduced following NR consumption compared with PL at 40 and 60% of VO2max (p < .0.05). Our findings suggest that acute nitrate supplementation before exercise at 3500 m does not reduce oxygen cost but may reduce blood lactate accumulation at lower intensity workloads.
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Withers, P. C., and S. S. Hillman. "A steady-state model of maximal oxygen and carbon dioxide transport in anuran amphibians." Journal of Applied Physiology 64, no. 2 (February 1, 1988): 860–68. http://dx.doi.org/10.1152/jappl.1988.64.2.860.
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A steady-state model, incorporating pulmonary ventilation, pulmonary diffusion capacity, cardiovascular transport capacity, and tissue diffusion capacity, was developed to describe the maximal O2 and CO2 transport capacity for an anuran amphibian (Bufo). Solution of the model by iterative calculation closely predicted 1) the empirical maximal O2 consumption (VO2max) for Bufo, 2) variation in empirical VO2max for three other genera (Rana, Xenopus, Scaphiopus), and the empirically observed effects on VO2max of 3) hypobaric hypoxia, 4) artificially induced anemia, and 5) beta-blockade of heart rate increment with activity. The model indicates that cardiovascular transport is the rate-limiting step to VO2max in amphibians and that an increase in circulatory O2 transport is a major physiological adaptation for increasing total aerobic capacity. CO2 transport and body fluid PCO2 values were primarily determined by pulmonary ventilatory capacity, and to a lesser extent by cardiovascular transport. The model should be generally applicable to other terrestrial vertebrates.
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Evans, D. L., and R. J. Rose. "Cardiovascular and respiratory responses in Thoroughbred horses during treadmill exercise." Journal of Experimental Biology 134, no. 1 (January 1, 1988): 397–408. http://dx.doi.org/10.1242/jeb.134.1.397.
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Six detrained Thoroughbred horses performed incremental treadmill tests. Maximal oxygen uptake (VO2max) was measured during exercise by analysis of expired gas. The relationships between oxygen consumption (VO2) and work rate, heart rate (HR), cardiac output (Q), stroke volume (SV) and arteriovenous oxygen content difference [C(a-v)O2] were examined during submaximal and maximal exercise. The relative contributions of blood flow and extraction of oxygen from muscle capillaries were assessed during exercise at VO2max. Mean VO2max was 129.7 +/− 2.9 (mean +/− S.E.M.) ml kg-1 min-1, which occurred at a mean speed of 8.0 ms-1, with the treadmill set at a slope of 10%. At VO2max the mean HR was 222 +/− 7 beats min-1. Maximal Q was 534 +/− 22 ml kg-1 min-1 and mean SV was 2.4 +/− 0.1 ml kg-1. Mean C(a-v)O2 was 24.5 +/− 1.2 ml 100 ml-1 blood. Linear relationships were found between VO2 and work rate, HR, Q and C(a-v)O2. Stroke volume did not increase significantly during exercise. Increasing metabolic rate during exercise was associated with linear increases in arterial haemoglobin concentration and oxygen content, and decreases in arterial oxygen partial pressures and haemoglobin saturation. We conclude that the relatively high VO2max in the detrained Thoroughbred racehorse is dependent on the generation of a large C(a-v)O2, despite development of hypoxaemia and haemoglobin desaturation, during strenuous exercise.
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Hong, Sung Hyun, Hyuk In Yang, Dong-Il Kim, Tomas I. Gonzales, Soren Brage, and Justin Y. Jeon. "Validation of Submaximal Step Tests and the 6-Min Walk Test for Predicting Maximal Oxygen Consumption in Young and Healthy Participants." International Journal of Environmental Research and Public Health 16, no. 23 (December 3, 2019): 4858. http://dx.doi.org/10.3390/ijerph16234858.
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Background: This study aimed to test the validity of three different submaximal tests (i.e., 3-min step test with 20.3-cm step box height (3MST20), 3-min step test with 30-cm step box height (3MST30), and 6-min walk test (6MWT)) in estimating maximal oxygen consumption (VO2max) in young and healthy individuals. Methods: The 3MST20, 3MST30, 6MWT, as well as the cardiopulmonary exercise test (CPET) were performed in 73 participants (37 men and 36 women; mean age: 30.8 ± 9.3 years). All participants visited the clinic three in a random order for anthropometric measurements, three submaximal tests, and the VO2max test. Multiple linear regression analyses were conducted to construct the VO2max prediction equations for each submaximal test. Results: The prediction equations developed based on multiple regression analyses for each submaximal tests were as follows: 3MST20: VO2max = 86.0 − 10.9 × sex (male = 1, female = 2) − 0.4 × age − 0.1 × weight − 0.1 × heart rate recovery at 30 s (HRR30s); 3MST30: VO2max = 84.5 − 10.2 × sex (male = 1, female = 2) − 0.4 × age − 0.1 × weight − 0.1 × HRR30s; and 6MWT: VO2max = 61.1 − 11.1 × sex (male = 1, female = 2) − 0.4 × age − 0.2 × weight − 0.2 × (distance walked·10−1). The estimated VO2max values based on formulated equations were 37.0 ± 7.9, 37.3 ± 7.6, and 36.9 ± 7.9 mL∙kg−1∙min−1 derived from the 3MST20, 3MST30, and 6MWT, respectively. These estimated VO2max values were not significantly different from the measured VO2max value, 37.3 mL∙kg−1∙min−1. The estimated VO2max based on the 3MST20, 3MST30, and 6MWT results explained 73.4%, 72.2%, and 74.4% of the variances in the measured VO2max (p < 0.001), respectively. Conclusions: The 3MST20, 3MST30, and 6MWT were valid in estimating VO2max in relatively young and healthy Asian individuals.
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Milošević, Milenko, Predrag Nemec, Vesna Nemec, and Miloš Milošević. "THE IMPACT OF 4-WEEK AEROBIC TRAINING ON THE AEROBIC STATUS OF TOP-LEVEL JUDOKAS." Facta Universitatis, Series: Physical Education and Sport 16, no. 1 (July 24, 2018): 201. http://dx.doi.org/10.22190/fupes171015018m.
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The aim of this paper is to use a training methodology that we believe to be a powerful incentive for cardiovascular and metabolic adaptation via individually programmed aerobic running directly through the consumption of oxygen. The experiment was carried out on a top judo team of 9 competitors in a 4-week training period. The distribution of training loads ranged between the anaerobic threshold and maximum oxygen consumption. In four weeks of training, the judokas significantly improved their results for maximum oxygen consumption (VO2max) from 2% to 15%, maximum relative oxygen consumption (VO2rel) from 2% to 16%, the Cooper test (K) from 2% to 15% and the speed at which the maximum amount of oxygen (vVO2max) is expended, from 2% to 15%. The judokas started from 64% to 83% of their genetic capacity in maximal oxygen consumption (VO2max), from 64% to 83% in maximum relative oxygen consumption (VO2rel) and 70% to 85% of the capacity at which they consumed the maximum amount of oxygen (vVO2max). After 4 weeks of training, 72% to 91% of the genetic capacity of maximum oxygen consumption (VO2max) ranged from 74% to 92% of the maximum relative oxygen consumption (VO2rel) and from 78% to 93% of the genetically projected capacity at the maximum amount of oxygen rate (vVO2max). In order to achieve these results, the judokas had to expend 943.80 to 1887.71 liters of oxygen ((∑VO2) to cross a distance ((∑ DT) from 67523.0 m to 102386.0 m and consume from 4719 to 9438.55 kilocalories ((∑ kcal).
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Robinson, D. M., R. W. Ogilvie, P. C. Tullson, and R. L. Terjung. "Increased peak oxygen consumption of trained muscle requires increased electron flux capacity." Journal of Applied Physiology 77, no. 4 (October 1, 1994): 1941–52. http://dx.doi.org/10.1152/jappl.1994.77.4.1941.
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The importance of the training-induced increase in mitochondrial capacity in realizing the increase in maximal O2 consumption (VO2max) of trained muscle was evaluated using an isolated perfused rat hindlimb preparation at a high blood flow (approximately 80 ml.min-1.100 g-1) during tetanic contractions. Rats trained for 8-–12 wk by treadmill running exhibited an approximately 25% increase in muscle VO2max (5.62 +/- 0.31 to 7.06 +/- 0.64 mumol.min-1.g-1), an increase in mitochondrial enzyme activity (approximately 70% for cytochrome oxidase and approximately 55% for NADH cytochrome-c reductase), and an increase in tissue capillarity (14%) that is expected to increase the O2 exchange capacity of the tissue. Muscle VO2max of sedentary (n = 34) and trained (n = 30) animals was determined, and electron transport capacity was acutely managed with myxothiazol, a tight-binding inhibitor of complex III. Inhibition of complex III was similar among 1) the low- and high-oxidative fibers and 2) the superficial and deep mitochondrial populations within muscle. Inhibition of NADH cytochrome-c reductase activity resulted in reductions in muscle VO2max with similar dose responses (mean effective dose of approximately 0.2 microM) of myxothiazol added to the perfusion medium. The extraction of O2 by the contracting muscle decreased as VO2max declined. The increase in muscle VO2max observed in the muscle of trained animals was eliminated when its electron transport capacity was reduced to that observed in normal sedentary rat muscle. Thus, the exercise-induced adaptation of an increased muscle mitochondrial content appears to be essential for trained muscle to exhibit its increased O2 flux capacity. The results of the present experiment illustrate the importance of mitochondrial adaptations in muscle remodeled by exercise training.
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Pluncevikj Gligoroska, Jasmina, Sanja Manchevska, Ljudmila Efremova, Lidija Todorovska, and Slobodan Nikolic. "Body composition and maximal oxygen consumption in adult soccer players in the Republic of Macedonia." Journal of Health Sciences 5, no. 3 (December 16, 2015): 85–92. http://dx.doi.org/10.17532/jhsci.2016.268.
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Introduction: The purpose of this study was to investigate the relationship between active and passive body mass components and maximal aerobic consumption (VO2max) in adult male soccer players.Methods: The study involved seven hundred (700) male soccer players, mean age 25.06 ± 4.41 years (range 18 to 35), divided in six age groups. Body composition was assessed according the anthropometric protocol by Matiegka, and relative muscle mass (MM%), bone (BM%) and fat (BF%) and absolute muscle mass (MMkg), bone (BMkg) and fat (BFkg) components were calculated. The Bruce protocol (incremental multistage treadmill test) was used for the estimation of maximal oxygen consumption.Results: Mean values of body mass components for total sample were as follows: muscle mass (MM%)= 52.75 ± 2.63%, bone mass (BM%)=16.63 ± 1.29% and body fat (BF%)=14.12 ± 1.54%. Mean VO2max was 48.89±5.17 ml/kg/minute. Relative muscle mass (MM%) showed similar values across age different groups (ANOVA: F=2.174; p=0.06) while absolute muscle mass (MMkg) showed tendency of increment with age (ANOVA: F=2.136; p=0.01). Body fat (BFkg and BF%) was statistically higher in the older groups (ANOVA F=3.737; p<0.01; ANOVA F=4.117; p<0.01). Weak positive correlation between VO2 max and muscle component (r=0.243; p<0.001) and a weak negative correlation between VO2max and body fat (r=-0.08;p<0.05) were found.Conclusions: Our results confirm the assumption that subjects with larger muscle mass have greater endurance and higher maximal oxygen consumption compared to subjects with larger body fat component.
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van den Tillaar, Roland, Erna von Heimburg, and Guro Strøm Solli. "Comparison of a Traditional Graded Exercise Protocol With a Self-Paced 1-km Test to Assess Maximal Oxygen Consumption." International Journal of Sports Physiology and Performance 15, no. 9 (October 1, 2020): 1334–39. http://dx.doi.org/10.1123/ijspp.2019-0843.
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Purpose: To compare the assessment of the maximal oxygen consumption (VO2max) in a traditional graded exercise test (GXT) with a 1-km self-paced running test on a nonmotorized treadmill in men and women. Methods: A total of 24 sport-science students (12 women: age 23.7 [7.7] y, body height 1.68 [0.02] m, body mass 66.6 [4.3] kg; 12 men: 22.1 [3.1] y, body height 1.82 [0.06] m, body mass 75.6 [11.0] kg) performed a traditional GXT on a motorized treadmill and a 1-km self-paced running test on a nonmotorized treadmill. VO2max, blood lactate, heart rate, and rating of perceived exertion, together with running velocity and duration at each test, were measured. Results: The main findings of the study were that the 1-km test produced significantly higher VO2max values (53.2 [9.9] vs 51.8 [8.8] mL/kg/min ) and blood lactate concentrations (11.9 [1.8] vs 11.1 [2.2] mmol/L) than the GXT (F ≥ 4.8, P ≤ .04, η2 ≥ .18). However, after controlling for sex, these differences were only present in men (60.6 [8.1] vs 58.1 [8.0] mL/kg/min , P = .027). Peak running velocity was higher in the GXT than in the 1-km test (15.7 [2.7] vs 13.0 [2.8] km/h). Men had higher VO2max values and running velocities than women in both tests. However, men and women used approximately similar pacing strategies during the 1-km test. Conclusions: Higher VO2max values were observed in a 1-km self-paced test than in the GXT. This indicates that a 1-km running test performed on a nonmotorized treadmill could serve as a simple and sport-specific alternative for the assessment of VO2max.
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Beyaz, Mehmet. "Evaluation of anaerobic threshold values and maximal oxygen consumption of elite Turkish football teams." Pakistan Journal of Medical and Health Sciences 15, no. 7 (July 30, 2021): 2229–33. http://dx.doi.org/10.53350/pjmhs211572229.
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In this study, it was aimed to determine, compare and evaluate the anaerobic threshold values and maximal oxygen consumption of the football players in the teams competing in the Turkcell Super league. The causal screening model was used in the study, and a total of 67 athletes from 3 teams in the Turkcell Super League participated. The names of the teams are coded as Team A, Team B and Team C. Data collection was performed using SensorMedics 29 c ergospirometry with the breath by breath method of maximal oxygen consumption. Heart rate values were recorded instantly using Polar watch. The V-Slope method was used for the anaerobic threshold value. While SPSS 25.0 package program was used for statistical evaluation, One Way ANOVA analysis was applied to compare 3 teams. As a result of the statistical evaluation, it was determined that there was a statistically significant difference between the teams in endurance training (heart rate), anaerobic threshold (heart rate), recovery (heart rate), and interval training (heart rate) parameters, however there was no statistically significant difference between the teams in VO2max values. As a result, although there is no statistically significant difference between the VO2max values between the teams, it is concluded that the athletes with higher values are more advantageous in other parameters. Keywords: Football, anaerobic threshold, maximal oxygen
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Weber, J. M., G. P. Dobson, W. S. Parkhouse, D. Wheeldon, J. C. Harman, D. H. Snow, and P. W. Hochachka. "Cardiac output and oxygen consumption in exercising Thoroughbred horses." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 253, no. 6 (December 1, 1987): R890—R895. http://dx.doi.org/10.1152/ajpregu.1987.253.6.r890.
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This study characterizes the effects of exercise on the cardiac output (Q) and the metabolic rate (VO2) of trained Thoroughbred racehorses. Heart rate, Q, and arteriovenous (a-v)O2 difference were measured at rest and at three levels of submaximal treadmill exercise (1.6 m/s walk and 3-4 m/s trot at 6% incline, and 6.5 m/s horizontal canter). Heart rate and (a-v)O2 difference were also measured during maximal exercise (12.5 m/s gallop, 5% incline) to obtain an estimate of maximum O2 uptake (VO2max). The walk, trot, and canter represented 25, 45, and 55% VO2max. Mean heart rate went from 48.9 (rest) to 197 beats/min (gallop). Q ranged from 106 (rest) to 571 ml.min-1.kg-1 (canter), and stroke volume went from 1.34 (rest) to a maximum of 1.58 liters (walk). Thoroughbreds were able to bring hematocrit from 38 (rest) to 63% (gallop), and this adjustment allowed them to reach an impressive (a-v)O2 difference of 23 vol%, which represents a fivefold increase over resting values. These outstanding athletes probably support an aerobic scope of 40-fold.
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Nunes, João Elias Dias, Heitor Santos Cunha, Renata Roland Teixeira, Foued S. Espindola, and Nádia Carla Cheik. "C-reactive protein is inversely and independently associated with maximal oxygen uptake in adolescents with obesity." Revista Brasileira de Educação Física e Esporte 34, no. 3 (September 30, 2020): 463–69. http://dx.doi.org/10.11606/issn.1981-4690.v34i3p463-469.
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The purposes of this study were: 1) investigate whether different markers of infl ammation (CRP and TNF-alpha) are correlated to cardiorespiratory fi tness in adolescents with obesity; 2) examine the association of these variables when adjusted by parameters of body composition. Were selected 57 individuals, 34 girls and 23 boys, with 16.4±1.56 years and body mass index 36.0±4.3 kg/m2. Anthropometric measurements (weight, height and abdominal circunference) and body composition (BMI, visceral fat, body fat) were assessment. Body composition was estimated by analyzer of tetrapolar bioelectrical impedance. Obesity was defi ned as BMI>95th percentile of the curve proposed by the Center for Diseases Control. Plasma TNF-alpha was measured by a quantitative two-site high-sensitivity enzyme immunoassay and CRP was measured by high-sensitivityimmunoturbidimetric assay. Graded maximal exercise testing was performed to obtain the maximum oxygen consumption (VO2max) and velocity associated with the VO2max (vVO2max). Signifi cant correlations of CRP with VO2max and vVO2max were found (r=-0.40 and r=-0,36, respectively). No correlations were observed between TNF-alpha and VO2max e vVO2max. CRP was associated to the VO2max and vVO2max independently of measurements of body composition. The CRP was independently and inversely associated with direct measurement of VO2max and the indirect variable of cardiorespiratory fitness vVO2max, in obese adolescents, even after adjustments in body composition, a potential confounding factor. No association was found between TNF-alpha and the parameters of cardiorespiratory fitness.
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Nunes, João Elias Dias, Heitor Santos Cunha, Renata Roland Teixeira, Foued S. Espindola, and Nádia Carla Cheik. "C-reactive protein is inversely and independently associated with maximal oxygen uptake in adolescents with obesity." Revista Brasileira de Educação Física e Esporte 34, no. 3 (November 20, 2020): 463–69. http://dx.doi.org/10.11606/1807-5509202000030463.
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The purposes of this study were: 1) investigate whether different markers of infl ammation (CRP and TNF-alpha) are correlated to cardiorespiratory fi tness in adolescents with obesity; 2) examine the association of these variables when adjusted by parameters of body composition. Were selected 57 individuals, 34 girls and 23 boys, with 16.4±1.56 years and body mass index 36.0±4.3 kg/m2. Anthropometric measurements (weight, height and abdominal circunference) and body composition (BMI, visceral fat, body fat) were assessment. Body composition was estimated by analyzer of tetrapolar bioelectrical impedance. Obesity was defi ned as BMI>95th percentile of the curve proposed by the Center for Diseases Control. Plasma TNF-alpha was measured by a quantitative two-site high-sensitivity enzyme immunoassay and CRP was measured by high-sensitivityimmunoturbidimetric assay. Graded maximal exercise testing was performed to obtain the maximum oxygen consumption (VO2max) and velocity associated with the VO2max (vVO2max). Signifi cant correlations of CRP with VO2max and vVO2max were found (r=-0.40 and r=-0,36, respectively). No correlations were observed between TNF-alpha and VO2max e vVO2max. CRP was associated to the VO2max and vVO2max independently of measurements of body composition. The CRP was independently and inversely associated with direct measurement of VO2max and the indirect variable of cardiorespiratory fitness vVO2max, in obese adolescents, even after adjustments in body composition, a potential confounding factor. No association was found between TNF-alpha and the parameters of cardiorespiratory fitness.
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Chu, Kelly S., Edward C. Rhodes, Jack E. Taunton, and Alan D. Martin. "Maximal Physiological Responses to Deep-Water and Treadmill Running in Young and Older Women." Journal of Aging and Physical Activity 10, no. 3 (July 2002): 306–13. http://dx.doi.org/10.1123/japa.10.3.306.
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The purpose of this study was to assess the difference in maximal physiological responses between an acute bout of deep-water running (DWR) and treadmill running (TMR) in young and older adults. Participants were 9 young and 9 older women who performed maximal DWR and TMR tests. Maximal measures included oxygen consumption (VO2max), heart rate (HRmax), ventilation (VE), respiratory-exchange ratio (RER), and blood lactate (BLac). The young women exhibited higher VO2max, HRmax, VE, and BLac than did the older women for both exercise conditions (p < .05). Lower VO2max and HRmax values were observed with DWR for both age groups (p < .05). No significant differences were found for VE, RER, and BLac in either group between exercise conditions, nor a significant interaction between exercise conditions or ages for any of the variables measured. The data suggest that although older adults exhibit lower maximal metabolic responses, differences between DWR and TMR responses occur irrespective of age.
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Hunt, Brian R., James D. George, Pat R. Vehrs, A. Garth Fisher, and Gilbert W. Fellingham. "Validity of a Submaximal 1-Mile Track Jog Test in Predicting VO2max in Fit Teenagers." Pediatric Exercise Science 12, no. 1 (February 2000): 80–90. http://dx.doi.org/10.1123/pes.12.1.80.
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The purpose of this study was to validate the ability of the 1-mile jog test to predict VO2max in fit teenagers. Forty-one males and 42 females performed the steady-state, submaximal jogging test on an indoor track, along with a maximal graded exercise test (GXT) on a treadmill. Open circuit calorimetry was used during the GXT to measure maximal oxygen consumption (VO2max). We generated the following age-specific prediction equation applicable to boys and girls 13–17 years old (n = 83, Radj = .88, SEE = 3.26 ml · kg−1 · min−1): VO2max = 92.91 + 6.50 × gender (0 = female, 1 = male) − 0.141 × body mass (kg) − 1.562 × jog time (min) − 0.125 × heart rate (bpm). Cross-validation results were acceptable (SEEpress = 3.44 ml · kg−1 · min−1). As a field test, the submaximal 1-mile jogging test may alleviate problems associated with pacing, motivation, discouragement, injury, and fatigue that are sometimes associated with maximal effort timed or distance run tests.
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Harms, C. A., and J. M. Stager. "Low chemoresponsiveness and inadequate hyperventilation contribute to exercise-induced hypoxemia." Journal of Applied Physiology 79, no. 2 (August 1, 1995): 575–80. http://dx.doi.org/10.1152/jappl.1995.79.2.575.
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Is inadequate hyperventilation a cause of the exercise-induced hypoxemia observed in some athletes during intense exercise? If so, is this related to low chemoresponsiveness? To test the hypothesis that exercise-induced hypoxemia, inadequate hyperventilation, and chemoresponsiveness are related, 36 nonsmoking healthy men were divided into hypoxemic (Hyp; n = 13) or normoxemic (Nor; n = 15) groups based on arterial oxygen saturation (SaO2; Hyp < or = 90%, Nor > 92%) observed during maximum O2 uptake (VO2max). Men with intermediate SaO2 values (n = 8) were only included in correlation analysis. Ventilatory parameters were collected at rest, during a treadmill maximal oxygen consumption (VO2max) test, and during a 5-min run at 90% VO2max. Chemoresponsiveness at rest was assessed via hypoxic ventilatory response (HVR) and hypercapnic ventilatory response (HCVR). VO2max was not significantly different between Nor and Hyp. SaO2 was 93.8 +/- 0.9% (Nor) and 87.7 +/- 2.0% (Hyp) at VO2max. End-tidal PO2 and the ratio of minute ventilation to oxygen consumption (VE/VO2) were lower while PETCO2 was higher for Hyp (P < or = 0.01). End-tidal PO2, end-tidal PCO2, and VE/VO2 correlated (P < or = 0.05) to SaO2 (r = 0.84, r = -0.70, r = 0.72, respectively), suggesting that differences in oxygenation were due to differences in ventilation. HVR and HCVR were significantly lower for Hyp. HVR was related to VE/VO2 (r = 0.43), and HCVR was related to the ratio of VE to CO2 production at VO2max (r = 0.61)
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Akay, Mehmet Fatih, Mustafa Mikail Ozciloglu, Ebru Cetin, Imdat Yarim, and Shahaboddin Daneshvar. "Estimating the maximal oxygen uptake with new prediction models for college-aged students using feature selection algorithm." New Trends and Issues Proceedings on Humanities and Social Sciences 5, no. 4 (September 17, 2018): 52–57. http://dx.doi.org/10.18844/prosoc.v5i4.3703.
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Maximum oxygen consumption (VO2max) is important to observe the endurance of the athletes and evaluate their performance.. Aim is to develop new prediction models for college-aged students using Support Vector Machine (SVM) with Relief-F feature selection algorithm. Ten different models consisting of the predictor variables gender, age, weight, height, maximal heart rate (HRmax), time, speed, Perceived Functional Ability scores (PFA-1 and PFA-2) and Physical Activity Rating score (PA-R) have been created by Relief-F scores for prediction of VO2max. The prediction models’ standard error of estimates (SEE’s) and multiple correlation coefficients (R’s) have been calculated for evaluating their performances. For comparison purposes, Tree Boost (TB) and Radial Basis Function Network (RBFN) based models have also been developed. The results show that the prediction model including PAR, speed, time, weight, PFA-1, gender and HRmax gives the lowest SEE with 6.42 mL.kg−1.min−1 and highest R with 0.79. Also, this study shows that the predictor variables HRmax and gender play a considerable role in VO2max prediction.
Keywords: Maximum oxygen uptake, machine learning, feature selection.
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Soares, Anne Danieli Nascimento, Samuel Penna Wanner, Elissa Stefane Silva Morais, Alexandre Sérvulo Ribeiro Hudson, Flaviano Santos Martins, and Valbert Nascimento Cardoso. "Supplementation with Saccharomyces boulardii Increases the Maximal Oxygen Consumption and Maximal Aerobic Speed Attained by Rats Subjected to an Incremental-Speed Exercise." Nutrients 11, no. 10 (October 2, 2019): 2352. http://dx.doi.org/10.3390/nu11102352.
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Benefits to the host metabolism resulting from Saccharomyces boulardii (Sb) supplementation have been described; however, no study has investigated the effects of this supplementation on aerobic metabolism and performance during physical exercise. Thus, in the present study, we addressed the effects of Sb supplementation on the rate of oxygen consumption (VO2), mechanical efficiency (external work divided by VO2), and aerobic performance of rats subjected to fatiguing, incremental-speed exercise. Twenty-six male Wistar rats were randomly divided into two groups: (1) non-supplemented, in which rats received 0.1 mL of a saline solution, and (2) Sb-supplemented, in which rats received 0.1 mL of a suspension containing 8.0 log10 colony-forming units. The rats received the treatments by gavage for 10 consecutive days; they were then subjected to fatiguing treadmill running. Sb supplementation did not change the VO2 values or mechanical efficiency during submaximal exercise intensities. In contrast, at fatigue, VO2MAX was increased by 12.7% in supplemented rats compared with controls (p = 0.01). Moreover, Sb improved aerobic performance, as evidenced by a 12.4% increase in maximal running speed attained by the supplemented rats (p < 0.05). We conclude that Sb supplementation for 10 days increases VO2MAX and aerobic performance in rats.
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Weatherwax, Ryan, Nigel Harris, Andrew E. Kilding, and Lance Dalleck. "Time Course Changes in Confirmed ‘True’ VO2max After Individualized and Standardized Training." Sports Medicine International Open 03, no. 02 (June 11, 2019): E32—E39. http://dx.doi.org/10.1055/a-0867-9415.
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AbstractThis study sought to examine time course changes in maximal oxygen consumption (VO2max) confirmed with verification testing following 12 weeks of standardized vs. individualized exercise training. Participants (N=39) were randomly allocated to differing exercise intensity prescription groups: ventilatory threshold (individualized) or % heart rate reserve (standardized). At baseline, 4, 8, and 12 weeks, participants completed maximal exercise testing with a verification protocol to confirm ‘true VO2max.’ VO2max in the standardized group changed from 24.3±4.6 ml·kg−1·min−1 at baseline to 24.7±4.6, 25.9±4.7, and 26.0±4.2 ml·kg−1·min−1 at week 4, 8, and 12, respectively, with a significant difference (p<0.05) in VO2max at week 8 and 12 compared to baseline. The individualized group had increases in VO2max from online 2 9.5±7.5 ml·kg−1·min−1 at baseline to 30.6±8.4, 31.4±8.4, and 32.8±8.6 ml·kg−1·min−1 at week 4, 8, and 12, respectively. In the individualized group, there were significant differences (p<0.05) in VO2max from baseline to week 8 and 12 and a significant increase in VO2max from week 8 to 1 online 2. Although not statistically significant, our preliminary data demonstrates a more rapid and potent improvement in VO2max when exercise intensity is individualized. This is the first investigation to employ use of the verification procedure to confirm ‘true VO2max’ changes following exercise training using ventilatory thresholds.
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Pompano, Laura M., and Jere D. Haas. "Increasing Iron Status through Dietary Supplementation in Iron-Depleted, Sedentary Women Increases Endurance Performance at Both Near-Maximal and Submaximal Exercise Intensities." Journal of Nutrition 149, no. 2 (January 10, 2019): 231–39. http://dx.doi.org/10.1093/jn/nxy271.
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ABSTRACT Background Iron deficiency persists as the most common micronutrient deficiency globally, despite having known detrimental effects on physical performance. Although iron supplementation and aerobic exercise have been examined individually and are known to improve physical performance, the impact of simultaneous iron supplementation and aerobic training remains unclear. Objective The aim of this study was to examine the individual and combined effects of iron supplementation and aerobic training on improving maximal and submaximal physical performance in iron-depleted, nonanemic (IDNA) women. We hypothesized that women receiving iron would improve their endurance performance but not their estimated maximal oxygen consumption (eVO2max). Methods Seventy-three sedentary, previously untrained IDNA (serum ferritin <25 µg/L and hemoglobin >110 g/L) women aged 18–26 y with a body mass index (kg/m2) of 17–25 participated in a double-blind, 8-wk, randomized controlled trial with a 2 × 2 factorial design including iron supplementation (42 mg elemental Fe/d) or placebo and aerobic exercise training (5 d/wk for 25 min at 75–85% of age-predicted maximum heart rate) or no training. Linear models were used to examine relations between training, supplement, and changes in the primary outcomes of observed maximal oxygen consumption (VO2peak) and eVO2max and ventilatory threshold (absolute oxygen consumption and percentage of maximum). Re-evaluation of a published meta-analysis was used to compare effects of iron supplementation on maximal oxygen consumption (VO2max) and VO2peak. Results There were significant training-by-supplement interactions for VO2peak, volume of oxygen consumption at the ventilatory threshold, and the percentage of eVO2max where the threshold occurred, with the iron-untrained group performing better than the placebo-untrained group. There was no beneficial effect of iron supplementation for VO2max (mean difference: 0.53; 95% CI: −0.75, 1.81; P = 0.42), but a significant benefit was observed for VO2peak (mean difference: 1.87; 95% CI: 0.15, 3.60; P = 0.03). Conclusions Iron supplementation increases endurance performance at submaximal and maximal (VO2peak) exercise intensities in IDNA women. However, increasing iron status does not increase eVO2max. This trial was registered at clinicaltrials.gov as NCT03002090.
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Constantinopol, M., J. H. Jones, E. R. Weibel, C. R. Taylor, A. Lindholm, and R. H. Karas. "Oxygen transport during exercise in large mammals. II. Oxygen uptake by the pulmonary gas exchanger." Journal of Applied Physiology 67, no. 2 (August 1, 1989): 871–78. http://dx.doi.org/10.1152/jappl.1989.67.2.871.
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Because the maximal rate of O2 consumption (VO2max) of the horse is 2.6 times larger than that of steers of equal size, we wondered whether their pulmonary gas exchanger is proportionately larger. Three Standardbred racehorses [body mass (Mb) = 447 kg] and three domestic steers (Mb = 474 kg) whose cardiovascular function at VO2max had been thoroughly studied (Jones et al. J. Appl. Physiol. 67: 862–870, 1989) were used to study their lungs by morphometry. The basic morphometric parameters were similar in both species. The nearly 2 times larger lung volumes of the horses caused the gas exchange surfaces and capillary blood volume to be 1.6 to 1.8 times larger. Morphometric pulmonary diffusing capacity was 2 times larger in the horse than in the steer; the 2.6-fold greater rate of O2 uptake thus required the alveolar-capillary PO2 difference to be 1.3 times larger in the horse than in the steer. Combining physiological and morphometric data, we calculated capillary transit time at VO2max to be 0.4–0.5 s. Bohr integration showed capillary blood to be equilibrated with alveolar air after 75 and 58% of transit time in horses and steers, respectively; horses maintain a smaller degree of redundancy in their pulmonary gas exchanger.
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Haidet, G. C. "Dynamic exercise in senescent beagles: oxygen consumption and hemodynamic responses." American Journal of Physiology-Heart and Circulatory Physiology 257, no. 5 (November 1, 1989): H1428—H1437. http://dx.doi.org/10.1152/ajpheart.1989.257.5.h1428.
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Seven senescent beagles and seven younger mature beagles were studied at rest, as well as during maximal and submaximal exercise on a motor-driven treadmill. Maximal exercise capacity was significantly (P less than 0.05) reduced, and maximal total body O2 consumption (VO2 max) was 31% lower in senescent beagles. VO2 was also significantly reduced in old dogs, when directly compared at the same relative workloads in old and younger mature dogs. However, VO2 was very similar in both groups during each of the absolute levels of directly comparable exercise. The observed age-related reduction in VO2 max was associated with a significant 25% reduction in maximal cardiac output (CO) in senescent beagles, and with an 11% reduction in maximal arteriovenous O2 difference. CO was also significantly reduced in old dogs at the same relative levels of submaximal exercise evaluated. Combined effects of reductions in stroke volume and in heart rate both contributed to the observed reductions in CO observed in senescent dogs during maximal exercise, as well as during relative levels of submaximal exercise. However, CO responses at each absolute level of submaximal exercise were similar in senescent and younger mature beagles, and the relationship between CO and VO2 was also similar in both groups. Increases in stroke volume significantly contributed to observed increases in CO beginning at the same relative level of exercise in both old and young dogs. Results of this study demonstrate that significant age-related changes in VO2max and in other associated hemodynamic parameters occur during maximal exercise. Many of these changes are also apparent when relative levels of submaximal exercise are directly compared in senescent and in younger mature beagles. However, most hemodynamic responses during absolute levels of exercise are similar in both groups, unless these parameters reflect the relative workload performed, indicating that these responses are appropriate for each absolute level of work that can be performed in the senescent dogs.
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Policarpo, Fernando, Pedro Valdivia-Moral, Maria do Socorro Luna-Cruz, Alex Véliz-Burgos, Juan Mansilla-Sepulveda, and Juan Guillermo Estay-Sepulveda. "Comparison between Different Prescription Methods for Aerobic Training in Young Adults." Sustainability 11, no. 22 (November 15, 2019): 6420. http://dx.doi.org/10.3390/su11226420.
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Anaerobic threshold and respiratory compensation are used to determine the intensity of aerobic exercise. This study aims to compare heart rate values relative to the percentages of 50%, 60%, 70%, and 80%, a comparison calculated through the reserve heart rate (HRR) and reserve oxygen consumption (VO2R) equations corresponding to the oxygen consumption obtained by the direct method. The sample was composed of 11 men and 10 women: mean age, 21.4 ± 2.8 years. Volunteers performed a maximal treadmill test in which oxygen uptake was measured using the VO2000® metabolic analyzer. The mean body fat percentage was 15.68 ± 8.02% corresponding to a lean body mass of 54.8 ± 13.0 kg and a maximal oxygen uptake (VO2max) of 56.0 ± 8.4 mL/Kg·min−1. The measured intensities (50%, 60%, 70% and 80% of VO2max) presented significant differences (p < 0.05) for each reference value. Mean values calculated by the HRR equation demonstrated a tendency to underestimate the intensities, while the values calculated by the VO2R equation showed a tendency to overestimate the intensities. As the main conclusion, it is pointed out that both methods were effective for determining the intensity of aerobic training. However, they presented significant differences, and the equations should be adjusted to increase precision. Thus, the use of HRR is recommended for the determination of training intensities.
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Martínez-Lagunas, Vanessa, and Ulrich Hartmann. "Validity of the Yo-Yo Intermittent Recovery Test Level 1 for Direct Measurement or Indirect Estimation of Maximal Oxygen Uptake in Female Soccer Players." International Journal of Sports Physiology and Performance 9, no. 5 (September 2014): 825–31. http://dx.doi.org/10.1123/ijspp.2013-0313.
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Purpose:To evaluate the validity of the Yo-Yo Intermittent Recovery Test Level 1 (YYIR1) for the direct assessment and the indirect estimation of maximal oxygen consumption (VO2max) in female soccer players compared with a maximal laboratory treadmill test (LTT).Methods:Eighteen female soccer players (21.5 ± 3.4 y, 165.6 ± 7.5 cm, 63.3 ± 7.4 kg; mean ± SD) completed an LTT and a YYIR1 in random order (1 wk apart). Their VO2max was directly measured via portable spirometry during both tests and indirectly estimated from a published non-gender-specific formula (YYIR1-F1).Results:The measured VO2max values in LTT and YYIR1 were 55.0 ± 5.3 and 49.9 ± 4.9 mL · kg−1 · min−1, respectively, while the estimated VO2max values from YYIR1-F1 corresponded to 45.2 ± 3.4 mL · kg−1 · min−1. Large positive correlations between the VO2max values from YYIR1 and LTT (r = .83, P < .001, 90% confidence interval = .64–.92) and YYIR1-F1 and LTT (r = .67, P = .002, .37–.84) were found. However, the YYIR1 significantly underestimated players’ VO2max by 9.4% compared with LTT (P < .001) with Bland-Altman 95% limits of agreement ranging from –20.0% to 1.4%. A significant underestimation from the YYIR1-F1 (P < .001) was also identified (17.8% with Bland-Altman 95% limits of agreement ranging from –31.8% to –3.8%).Conclusions:The YYIR1 and YYIR1-F1 are not accurate methods for the direct assessment or indirect estimation of VO2max in female soccer players. The YYIR1-F1 lacks gender specificity, which might have been the reason for its larger error.
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Daida, H., T. G. Allison, B. D. Johnson, R. W. Squires, and L. J. Olson. "GENDER DIFFERENCES IN MAXIMAL OXYGEN CONSUMPTION (VO2max) DURING GRADED EXERCISE TESTING IN CHRONIC HEART FAILURE (CHF)." Medicine & Science in Sports & Exercise 27, Supplement (May 1995): S159. http://dx.doi.org/10.1249/00005768-199505001-00893.
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Ingham, Stephen A., Jamie S. Pringle, Sarah L. Hardman, Barry W. Fudge, and Victoria L. Richmond. "Comparison of Step-Wise and Ramp-Wise Incremental Rowing Exercise Tests and 2000-m Rowing Ergometer Performance." International Journal of Sports Physiology and Performance 8, no. 2 (March 2013): 123–29. http://dx.doi.org/10.1123/ijspp.8.2.123.
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Purpose:This study examined parameters derived from both an incremental step-wise and a ramp-wise graded rowing exercise test in relation to rowing performance.Methods:Discontinuous step-wise incremental rowing to exhaustion established lactate threshold (LT), maximum oxygen consumption (VO2maxSTEP), and power associated with VO2max (W VO2max). A further continuous ramp-wise test was undertaken to derive ventilatory threshold (VT), maximum oxygen consumption (VO2maxRAMP), and maximum minute power (MMW). Results were compared with maximal 2000-m ergometer time-trial power.Results:The strongest correlation with 2000-m power was observed for MMW (r = .98, P < .001), followed by W VO2max (r = .96; P < .001). The difference between MMW and W VO2max compared with the mean of MMW/W VO2max showed a widening bias with a greater difference coincident with greater power. However, this bias was reduced when expressed as a ratio term and when a baseline VO2 was accounted for. There were no differences (P = .85) between measures of VO2maxSTEP and VO2maxRAMP; rather, the measures showed strong association (r = .97, P < .001, limits of agreement = −0.43 to 0.33 L/min). The power at LT and VT did not differ (P = .6), and a significant association was observed (r = .73, P = .001, limits of agreement = −54.3 to 20.2 W, SEE = 26.1).Conclusions:This study indicates that MMW demonstrates a strong association with ergometer rowing performance and thus may have potential as an influential monitoring tool for rowing athletes.
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Decroix, Lieselot, Kevin De Pauw, Carl Foster, and Romain Meeusen. "Guidelines to Classify Female Subject Groups in Sport-Science Research." International Journal of Sports Physiology and Performance 11, no. 2 (March 2016): 204–13. http://dx.doi.org/10.1123/ijspp.2015-0153.
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Aim:To review current cycling-related sport-science literature to formulate guidelines to classify female subject groups and to compare this classification system for female subject groups with the classification system for male subject groups.Methods:A database of 82 papers that described female subject groups containing information on preexperimental maximal cycle-protocol designs, terminology, biometrical and physiological parameters, and cycling experience was analyzed. Subject groups were divided into performance levels (PLs), according to the nomenclature. Body mass, body-mass index, maximal oxygen consumption (VO2max), peak power output (PPO), and training status were compared between PLs and between female and male PLs.Results:Five female PLs were defined, representing untrained, active, trained, well-trained, and professional female subjects. VO2max and PPO significantly increased with PL, except for PL3 and PL4 (P < .01). For each PL, significant differences were observed in absolute and relative VO2max and PPO between male and female subject groups. Relative VO2max is the most cited parameter for female subject groups and is proposed as the principal parameter to classify the groups.Conclusion:This systematic review shows the large variety in the description of female subject groups in the existing literature. The authors propose a standardized preexperimental testing protocol and guidelines to classify female subject groups into 5 PLs based on relative VO2max, relative PPO, training status, absolute VO2max, and absolute PPO.
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Lentz, Liana, Jason R. Randall, Christine A. Guptill, Douglas P. Gross, Ambikaipakan Senthilselvan, and Donald Voaklander. "The Association Between Fitness Test Scores and Musculoskeletal Injury in Police Officers." International Journal of Environmental Research and Public Health 16, no. 23 (November 23, 2019): 4667. http://dx.doi.org/10.3390/ijerph16234667.
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A police officer’s career is hazardous and physically demanding. In order to perform occupational tasks effectively and without injury, officers require adequate physical abilities. The aim of this study was to investigate the relationship between scores on several fitness tests and musculoskeletal injury in a group of municipal police officers. This retrospective study used existing data to examine the relationship between risk of injury and fitness test performance. Injured and uninjured police officers scored significantly differently on several fitness measures. A multivariate regression indicated that a combination of age, sex, number of pull ups completed and maximal oxygen consumption (VO2max) best explained injury risk. Additionally, the findings indicated an interaction between sex and VO2max, and so the effect of VO2max on injury risk cannot be understood without accounting for sex.
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Jang, Won Young, Dong Oh Kang, Yoonjee Park, Jieun Lee, Woohyeun Kim, Jah Yeon Choi, Seung-Young Roh, et al. "Validation of FRIEND and ACSM Equations for Cardiorespiratory Fitness: Comparison to Direct Measurement in CAD Patients." Journal of Clinical Medicine 9, no. 6 (June 17, 2020): 1889. http://dx.doi.org/10.3390/jcm9061889.
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The regression equation of the American College of Sports Medicine (ACSM) was a preferred method for estimating maximal oxygen consumption (VO2max). Recently, a more precise equation from the fitness registry and the importance of exercise national database (FRIEND) for healthy people was developed. This study compared VO2max estimated by the ACSM and FRIEND equations to VO2max directly measured in coronary artery disease (CAD) patients. Overall, 293 CAD patients who participated in cardiac rehabilitation between June 2015 and December 2018 were analyzed. Directly measured VO2max values were compared to the ACSM and FRIEND equations. The directly measured VO2max was significantly different from the estimated VO2max by ACSM equation (24.16 vs. 28.7 mL/kg/min, p < 0.001), which was overestimated by 20% in men and 16% in women. However, there was no statistically significant difference between the directly measured VO2max and the estimated VO2max by the FRIEND equation. (24.16 vs. 24.15 mL/kg/min, p = 0.986). In CAD patients, the estimated VO2max from the ACSM equation was significantly higher than the directly measured VO2max. In addition, estimated cardiorespiratory fitness (CRF) by the FRIEND equation showed similar results with directly measured CRF. As a result, the FRIEND equation can predict CRF more accurately than the ACSM.
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Eyileten, Ceren, Alex Fitas, Daniel Jakubik, Pamela Czajka, Anna Mróz, Anna Czajkowska, Katarzyna Witek, et al. "Alterations in Circulating MicroRNAs and the Relation of MicroRNAs to Maximal Oxygen Consumption and Intima–Media Thickness in Ultra-Marathon Runners." International Journal of Environmental Research and Public Health 18, no. 14 (July 6, 2021): 7234. http://dx.doi.org/10.3390/ijerph18147234.
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The impact of long-term training on cardiovascular disease (CVD) is not clear. Carotid intima–media thickness (CIMT) test is recommended as a useful measure to diagnose the early stages of atherosclerosis. MicroRNAs (miRNAs) are altered due to endurance exercise and can be promising biomarkers of pathophysiological changes. We aimed to evaluate the association of circulating miRNAs with physical fitness and markers of atherosclerosis in ultra-marathon runners. Ultra-marathon runners had 28-fold upregulation of miR-125a-5p expressions compared to control individuals (p = 0.002), whereas let-7e and miR-126 did not differ statistically between ultra-marathon runners and controls. In the ultra-marathon runners’ group, negative correlations were observed between VO2max/kg and relative expression of miR-125a-5p and miR-126 (r = −0.402, p = 0.028; r = −0.438, p = 0.032, respectively). Positive correlations were observed between CIMT and miR-125a-5p and miR-126 (r = 0.388, p = 0.050; r = 0.504, p = 0.023, respectively) in ultra-marathon runners. Individuals with the highest quartile of VO2max/kg had 23-fold lower miR-126 expression in comparison to subgroups with lower VO2max/kg (p = 0.017). Our results may indicate that both miRNAs may serve as a biomarker for early pathological changes leading to atherosclerosis burden in athletes. Furthermore, the association between miRNAs and traditional risk factors for CVD indicate a possible use of these molecules as early biomarkers of future cardiovascular health.
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Peric, R., and Z. Nikolovski. "Can metabolic thresholds be used as exercise intensity markers in adult men with obesity – fat burn points used as an exercise marker." Comparative Exercise Physiology 16, no. 2 (February 10, 2020): 113–19. http://dx.doi.org/10.3920/cep190035.
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We aimed to determine the exercise intensity eliciting the highest (FATmax) and the lowest (FATmin) fat oxidation rate in sedentary men with obesity and to examine if these intensities correlate with their individual aerobic (AeT) and anaerobic (AnT) thresholds, respectively. Nineteen obese males performed breath-by-breath analysis to assess maximal oxygen consumption (VO2max) and to calculate their fat oxidation rate. Pearson correlation coefficient (r), coefficient of determination (R2) and paired t-test were used to evaluate VO2 at AeT and at FATmax and VO2 at AnT and at FATmin, respectively. FATmax and AeT occurred at 42.80±2.68% of VO2max and 43.02±2.73% of VO2max, while FATmin and AnT occurred at 53.40±3.65% of VO2max and 53.38±3.65% of VO2max, respectively. A high correlations were found between intensities matching FATmax and AeT (r=0.86, P<0.01) and those at FATmin and at AnT (r=0.99, P<0.01). The existing correlations suggest that metabolic thresholds may be used as exercise intensity markers assuring more tailored exercise approach in men with obesity.
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Santiago, Mayra C., Arthur S. Leon, and Robert C. Serfass. "Failure of 40 Weeks of Brisk Walking to Alter Blood Lipids in Normolipemic Women." Canadian Journal of Applied Physiology 20, no. 4 (December 1, 1995): 417–28. http://dx.doi.org/10.1139/h95-033.
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Sedentary, eumenorrheic women (N = 27) 22 to 40 years of age, with high baseline levels of plasma high-density lipoprotein cholesterol, were randomly assigned to a walking (n = 16) or a control group (n = 11). The training program involved treadmill walking 4.8 km (3.0 miles) four times a week for 40 weeks at a mean intensity of 72% maximal heart rate. Aerobic power (VO2max) was improved by 22%, but no training effect was observed in body composition variables or blood lipid/lipoprotein levels. Despite additional increments in exercise intensity over the final 20 weeks of training, most of the improvement in VO2max was observed over the first 20 weeks of the study. Exercising subjects' baseline levels of plasma HDL-C were found to be inversely associated with the change (delta) scores in the lipoprotein (r = −0.51, p <.05). Key words: maximal oxygen consumption, high-density lipoprotein cholesterol
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Di Prampero, P. E., C. Capelli, P. Pagliaro, G. Antonutto, M. Girardis, P. Zamparo, and R. G. Soule. "Energetics of best performances in middle-distance running." Journal of Applied Physiology 74, no. 5 (May 1, 1993): 2318–24. http://dx.doi.org/10.1152/jappl.1993.74.5.2318.
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Oxygen consumption (VO2) and blood lactate concentration were determined during constant-speed track running on 16 runners of intermediate level competing in middle distances (0.8–5.0 km). The energy cost of track running per unit distance (Cr) was then obtained from the ratio of steady-state VO2, corrected for lactate production, to speed; it was found to be independent of speed, its overall mean being 3.72 +/- 0.24 J.kg-1 x m-1 (n = 58; 1 ml O2 = 20.9 J). Maximal VO2 (VO2max) was also measured on the same subjects. Theoretical record times were then calculated for each distance and subject and compared with actual seasonal best performances as follows. The maximal metabolic power (Er max) a subject can maintain in running is a known function of VO2max and maximal anaerobic capacity and of the effort duration to exhaustion (te). Er max was then calculated as a function of te from VO2max, assuming a standard value for maximal anaerobic capacity. The metabolic power requirement (Er) necessary to cover a given distance (d) was calculated as a function of performance time (t) from the product Crdt-1 = Er. The time values that solve the equality Er max(te) = Er(t), assumed to yield the theoretical best t, were obtained by an iterative procedure for any given subject and distance and compared with actual records.
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Bozzini, B. N., J. K. Pellegrino, A. J. Walker, B. A. McFadden, A. N. Poyssick, and S. M. Arent. "Running economy and its correlation to performance and fitness variables in recreationally-trained distance runners." Comparative Exercise Physiology 16, no. 2 (February 10, 2020): 107–12. http://dx.doi.org/10.3920/cep190039.
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Specific physiological attributes such as maximal oxygen consumption (VO2max) and running economy (RE) have been suggested to help predict long distance performance in endurance athletes. Despite this, investigations of RE have yielded conflicting results, particularly when comparing elite and recreational runners. The purpose of this study was to illustrate correlations between RE, expressed as submaximal oxygen consumption at a given speed, and time trial (TT) performance in addition to various fitness markers in endurance-trained individuals. Trained distance runners (n=21) performed a battery of tests over three sessions to provide measurements of RE at 2.68 m/s (RE2.68) and 4.25 m/s (RE4.25), TT performance, VO2max, velocity at ventilatory threshold (VVT), and body composition. Pearson-product moment correlations, defined as weak (r≥0.25), moderate (r≥0.45), and strong (r≥0.65), were calculated among all measures and significance was set at P<0.05. The findings suggested that faster TT performance was significantly (P<0.05) correlated to a higher VO2max (r=-0.86) and lower body fat percentage (BF%; r=0.78). However, TT performance displayed only a weak trend to RE4.25 (r=-0.40, P=0.07) and was not correlated to RE2.68 (r=0.15; P>0.05). Additionally, better RE4.25 (i.e. decreased submaximal oxygen consumption) was associated with a lower VO2max (r=0.66, P<0.05) and an increased BF% (r=-0.46, P<0.05). RE2.68 revealed no significant relationships with these measures. Comparable to their elite counterparts, higher aerobic capacity is strongly linked to performance in recreational distance runners, though in this cohort RE only weakly related to performance at the faster velocity. Finally, the inverse relationship between markers of overall fitness and RE suggests that enhanced RE may be an adaptive response to a limited physiological capacity in this population.
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Mohammed, Zerf, Boras Fatima Zohar, Benali Gourar, Bengoua Ali, and Mokkedes Moulay Idriss. "VO2max levels as a pointer of physiological training status among soccer players." Acta Facultatis Educationis Physicae Universitatis Comenianae 58, no. 2 (November 1, 2018): 112–21. http://dx.doi.org/10.2478/afepuc-2018-0010.
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Abstract The purpose of the current study was to evaluate the Aerobic endurance training as indicators of physiological training status among male soccer players. A total of 138 well-trained first division soccer players under 18 years were tested. Testing was based on the Cooper test as a one of simple tests to estimate VO2max. BMI and BFP as valued anthropometric measurements to control body change relative to maximal oxygen consumption during dynamic exercise with large muscle groups benefit training time soccer training experience. Performance in this experience was based on the subjection that 60 ml/kg/min of VO2max is the minimum fitness requirement for male soccer players to play at the elite level. Admit in this study as a protocol to categorise our sample into two groups (up and under the range VO2max ± 60 ml/kg/min) and it was based on statistics applied and the design used. Our results highlighted the importance of aerobic performance up to 60 ml/kg/min as the minimum fitness requirement to enhance the players' aerobic capacity allied to maximal heart rate relative to BFP levels as a better parameter in comparison with BMI for the prediction of low VO2max concomitant to the physiological training status as requests soccer performance demand.
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Suminski, Richard R., Larry T. Wier, Walker Poston, Brian Arenare, Anthony Randles, and Andrew S. Jackson. "The Effect of Habitual Smoking on Measured and Predicted VO2max." Journal of Physical Activity and Health 6, no. 5 (September 2009): 667–73. http://dx.doi.org/10.1123/jpah.6.5.667.
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Background:Nonexercise models were developed to predict maximal oxygen consumption (VO2max). While these models are accurate, they don’t consider smoking, which negatively impacts measured VO2max. The purpose of this study was to examine the effects of smoking on both measured and predicted VO2max.Methods:Indirect calorimetry was used to measure VO2max in 2,749 men and women. Physical activity using the NASA Physical Activity Status Scale (PASS), body mass index (BMI), and smoking (pack-y = packs·day * y of smoking) also were assessed. Pack-y groupings were Never (0 pack-y), Light (1–10), Moderate (11–20), and Heavy (>20). Multiple regression analysis was used to examine the effect of smoking on VO2max predicted by PASS, age, BMI, and gender.Results:Measured VO2max was significantly lower in the heavy smoking group compared with the other pack-y groups. The combined effects of PASS, age, BMI, and gender on measured VO2max were significant. With smoking in the model, the estimated effects on measured VO2max from Light, Moderate, and Heavy smoking were –0.83, –0.85, and –2.56 ml·kg−1·min−1, respectively (P < .05).Conclusions:Given that 21% of American adults smoke and 12% of them are heavy smokers, it is recommended that smoking be considered when using nonexercise models to predict VO2max.
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Bauerle, O., and M. Younes. "Role of ventilatory response to exercise in determining exercise capacity in COPD." Journal of Applied Physiology 79, no. 6 (December 1, 1995): 1870–77. http://dx.doi.org/10.1152/jappl.1995.79.6.1870.
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The progression of chronic obstructive pulmonary disease (COPD) is generally associated with decreased exercise capacity. Differences in forced expired volume in 1 s (FEV1) among patients account for only a fraction of the variability in maximal oxygen consumption (VO2max). We hypothesized that variability in ventilatory response to exercise and in inspiratory mechanics and body mass index contributes importantly to variability in VO2max in this disease. We analyzed the files of 53 patients with established diagnosis of COPD who underwent a recent symptom-limited exercise test. We used inspiratory capacity and maximum inspiratory flow as measures of variability in inspiratory mechanics. The minute ventilation (VE) at the subject's VO2max was divided by the predicted in a normal subject at the same VO2 to obtain a ratio (VE,max/VE,pred). The ventilatory response during exercise provided the best correlation with peak VO2 (r = 0.62). FEV1 and inspiratory capacity also correlated with peak oxygen consumption but not as well as the ventilatory response (r = 0.49 and r = 0.46, respectively). Maximum inspiratory flow and body mass index showed only weak positive correlations (r = 0.23, not significant). The stepwise analysis generated the following equation: VO2max (%predicted) = (77.26 x VE,pred/VE,max) + [0.45 x FEV1 (%predicted)] - 23.66; r = 0.76, P < 0.001. We conclude that variability in the ventilatory response during exercise is one of the main determinants of variability in exercise capacity in COPD patients.
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Kayar, S. R., H. Hoppeler, J. H. Jones, K. Longworth, R. B. Armstrong, M. H. Laughlin, S. L. Lindstedt, J. E. Bicudo, K. Groebe, and C. R. Taylor. "Capillary blood transit time in muscles in relation to body size and aerobic capacity." Journal of Experimental Biology 194, no. 1 (September 1, 1994): 69–81. http://dx.doi.org/10.1242/jeb.194.1.69.
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The mean minimal transit time for blood in muscle capillaries (tc) was estimated in six species, spanning two orders of magnitude in body mass and aerobic capacity: horse, steer, dog, goat, fox and agouti. Arterial (CaO2) and mixed venous (CvO2) blood O2 concentrations, blood hemoglobin concentrations ([Hb]) and oxygen uptake rates were measured while the animals ran on a treadmill at a speed that elicited the maximal oxygen consumption rate (VO2max) from each animal. Blood flow to the muscles (Qm) was assumed to be 85% of cardiac output, which was calculated using the Fick relationship. Total muscle capillary blood volume (Vc) and total muscle mitochondrial volume were estimated by morphometry, using a whole-body muscle sampling scheme. The tc was computed as Vc/Qm. The tc was 0.3-0.5 s in the 4 kg foxes and agoutis, 0.7-0.8 s in the 25 kg dogs and goats, and 0.8-1.0 s in the 400 kg horses and steers. The tc was positively correlated with body mass and negatively correlated with transcapillary O2 release rate per unit capillary length. Mitochondrial content was positively correlated with VO2max and with the product of Qm and [Hb]. These data suggested that Qm, Vc, maximal hemoglobin flux, and consequently tc, are co-adjusted to result in muscle O2 supply conditions that are matched to the O2 demands of the muscles at VO2max.