Letteratura scientifica selezionata sul tema "Cardiorespiratory fitness (vo2max)"

Cardiorespiratory fitness (CRF) is an important indicator of adolescent cardiovascular well-being and future cardiometabolic health but not always feasible to measure. The purpose of this study was to estimate the concurrent validity of the non-exercise test (NET) for adolescents against the Progressive Aerobic Capacity Endurance Run (PACER®) and direct measures of VO2max as well as to examine the concurrent validity of the PACER® with a portable metabolic system (K4b2™). Forty-six adolescents (12–17 years) completed the NET prior to performing the PACER® while wearing the K4b2™. The obtained VO2max values were compared using linear regression, intra-class correlation (ICC), and Bland–Altman plots, and α was set at 0.05. The VO2max acquired directly from the K4b2™ was significantly correlated to the VO2max indirectly estimated from the NET (r = 0.73, p < 0.001, r2 = 0.53, ICC = 0.67). PACER® results were significantly related to the VO2max estimates from the NET (r = 0.81, p < 0.001, r2 = 0.65, ICC = 0.72). Direct measures from the K4b2™ were significantly correlated to the VO2max estimates from the PACER® (r = 0.87, p < 0.001, r2 = 0.75, ICC = 0.93). The NET is a valid measure of CRF in adolescents and can be used when an exercise test is not feasible.

High levels of cardiovascular fitness (CRF) and physical activity (PA) are associated with decreased mortality and risk to develop metabolic diseases. The independent contributions of CRF and PA to metabolic disease risk factors are unknown. We tested the hypothesis that runners who run consistently >50 km/wk and/or >2 marathons/yr for the last 5 years have superior metabolic fitness compared to matched sedentary subjects (CRF, age, gender, and BMI). Case-control recruitment of 31 pairs of runner-sedentary subjects identified 10 matched pairs with similar VO2max(mL/min/kg) (similar-VO2max). The similar-VO2maxgroup was compared with a group of age, gender, and BMI matched pairs who had the largest difference in VO2max(different-VO2max). Primary outcomes that defined metabolic fitness including insulin response to an oral glucose tolerance test, fasting lipids, and fasting insulin were superior in runners versus sedentary controls despite similar VO2max. Furthermore, performance (velocity at VO2max, running economy), improved exercise metabolism (lactate threshold), and skeletal muscle levels of mitochondrial proteins were superior in runners versus sedentary controls with similar VO2max. In conclusion subjects with a high amount of PA have more positive metabolic health parameters independent of CRF. PA is thus a good marker against metabolic diseases.

ABSTRACT Objective: To associate the Maximal Oxygen Uptake (VO2max) with body fat percentage (%BF), and to establish the best VO2max cutoff point for predicting risk %BF in teenagers. Methods: This study was carried out with 979 subjects aged 10 to 18.8 years, 556 (56.8%) girls. The 20 m shuttle run protocol determined the VO2max, which was analyzed in quintiles and in a numeric scale. Cutaneous fold equations determined the %BF, later classified as risk to health/obesity when >25 in girls and >20 in boys. Regression method was used - Odds Ratio (OR) and Receiver Operating Characteristics Curve (ROC curve) with α <5%. Results: From the total number of valid cases, 341 (65.6%) girls and 202 (53.2%) boys presented %BF of risk, and a larger proportion of %BF of risk was observed in the 1st quintile of the VO2max for both genders. There was inverse association between VO2max and %BF of risk from the 4th quintile (OR 1.84, 95%CI 1.05-3.24) until the 1st quintile (OR 4.74, 95%CI 2.44-9.19) for girls, and from the 2nd quintile (OR 2.99, 95%CI 1.48-6.00) until the 1st quintile (OR 5.60, 95%CI 2.64-11.87) for boys. As analytic highlights, VO2max Cutoff points for prediction of %BF of risk were ≤40.9 mL/kg-1/min-1 (AUC: 0.65; p<0.001) for girls and ≤44.8 mL/kg-1/min-1 (AUC: 0.66; p<0.001)for boys.. Conclusions: VO2max was inversely associated to the %BF, and VO2max cutoff points for prediction of %BF of risk are important results to generate action to fight early obesity.

AbstractThe purpose of this study was to investigate the correlation between the seismocardiogram and cardiorespiratory fitness. Cardiorespiratory fitness can be estimated as VO2max using non-exercise algorithms, but the results can be inaccurate. Healthy subjects were recruited for this study. Seismocardiogram and electrocardiogram were recorded at rest. VO2max was measured during a maximal effort cycle ergometer test. Amplitudes and timing intervals were extracted from the seismocardiogram and used in combination with demographic data in a non-exercise prediction model for VO2max. 26 subjects were included, 17 females. Mean age: 38.3±9.1 years. The amplitude following the aortic valve closure derived from the seismocardiogram had a significant correlation of 0.80 (p<0.001) to VO2max. This feature combined with age, sex and BMI in the prediction model, yields a correlation to VO2max of 0.90 (p<0.001, 95% CI: 0.83–0.94) and a standard error of the estimate of 3.21 mL·kg−1·min−1 . The seismocardiogram carries information about the cardiorespiratory fitness. When comparing to other non-exercise models the proposed model performs better, even after cross validation. The model is limited when tracking changes in VO2max. The method could be used in the clinic for a more accurate estimation of VO2max compared to current non-exercise methods.

The purpose of the present study was to analyze if the association between sex with cardiorespiratory and muscular fitness is independent of physical activity, sports practice and sedentary behavior in young people. A cross-sectional study involving 729 participants aged 10 to 17 years. Physical activity, sports practice and sedentary behavior were assessed through a questionnaire. Cardiorespiratory fitness was measured using 20m shuttle run test and were analyzed: VO2max, number of laps and health-related criteria. Muscular fitness was assessed with 90o push-up test and number of repetition and health-related criteria was analyzed. Multiple linear regression was used to estimate β coeficients and Poisson regression estimated prevalence ratios (PR). Male sex was associated to higher cardiorespiratory fitness (VO2max β = 9.04 to 9.77, Laps PR=1.67 to 1.80, health-related criteria PR=2.03 to 2.09) and the same occurred with muscular fitness (repetitions PR=2.81 to 3.01, health-related criteria PR=1.91 to 2.09). Similarly, the stratification of the sample according to physical activity, sports practice and sedentary behavior did not change the associations between sex with cardiorespiratory (VO2max β=8.07 to 10.00, Laps PR=1.49 to 1.85, health-related criteria PR=1.64 to 2.27) and muscular fitness (repetitions PR=2.24 to 3.22, health-related criteria PR=1.76 to 2.06). These data suggest that higher cardiorespiratory and muscular fitness in males could not be attributed to physical activity, sports practice or sedentary behavior in young people.

Background. Good cardiorespiratory fitness (high VO2max) has beneficial effects on morbidity and mortality. Therefore, a tool to estimate VO2max in daily clinical practice is of great value for preventing chronic diseases in healthy adults. This study aimed at exploring the cardiometabolic profile in a representative Swiss working population. Based on these insights, a regression model was derived revealing factors associated with VO2max. Methods. Cross-sectional data of 337 healthy and full-time employed adults recruited in the Basel region, Switzerland, were collected. Anthropometric measurements to compute body mass index (BMI) and waist circumference (WC) were performed. A 20-meter shuttle run test was conducted to determine individual VO2max. Heart rate (HR) was measured at rest, during maximal exertion, and two minutes after exercise. Systolic (SBP) and diastolic blood pressure (DBP) were assessed at rest and after exercise. A multiple linear regression model was built to identify a set of nonexercise predictor variables of VO2max. Results. Complete data of 303 individuals (63% male) aged 18 to 61 years (mean 33 ± 12 years) were considered for analysis. The regression model (adjusted R2 = 0.647, SE = 5.3) identified sex (β = -0.699, p < 0.001), WC (β = -0.403, p < 0.001), difference of maximal to resting HR (β = 0.234, p < 0.001), smoking (β = -0.171, p < 0.001), and age (β = -0.131, p < 0.01) as the most important factors associated with VO2max, while BMI, SBP, and DBP did not contribute to the regression model. Conclusions. This study introduced a simple model to evaluate VO2max based on nonexercise parameters as part of daily clinical routine without needing a time-consuming, cost-intense, and physically demanding direct assessment of VO2max. Knowledge about VO2max may help identifying individuals at increased cardiovascular risk and may provide the basis for health counselling and tailoring preventive measures.

AbstractObjectiveTo examine the association between cardiorespiratory fitness and dietary patterns in adolescents.DesignFood choice was assessed using the validated New Zealand Adolescent FFQ. Principal components analysis was used to determine dietary patterns. Trained research assistants measured participants’ height and body mass. Cardiorespiratory fitness was assessed in a subset of participants using the multistage 20 m shuttle run. The level and stage were recorded, and the corresponding VO2max was calculated. Differences in mean VO2max according to sex and BMI were assessed using t tests, while associations between cardiorespiratory fitness and dietary patterns were examined using linear regression analyses adjusted for age, sex, school attended, socio-economic deprivation and BMI.SettingSecondary schools in Otago, New Zealand.SubjectsStudents (n 279) aged 14–18 years who completed an online lifestyle survey during a class period.ResultsPrincipal components analysis produced three dietary patterns: ‘Treat Foods’, ‘Fruits and Vegetables’ and ‘Basic Foods’. The 279 participants who provided questionnaire data and completed cardiorespiratory fitness testing had a mean age of 15·7 (sd 0·9) years. Mean VO2max was 45·8 (sd 6·9) ml/kg per min. The ‘Fruits and Vegetables’ pattern was positively associated with VO2max in the total sample (β=0·04; 95 %CI 0·02, 0·07), girls (β=0·06; 95 % CI 0·03, 0·10) and boys (β=0·03; 95 % CI 0·01, 0·05).ConclusionsThese results indicate that increase in cardiorespiratory fitness was associated with a healthier dietary pattern, suggesting both should be targeted as part of a global lifestyle approach. Longitudinal studies are needed to confirm this association in relation to health outcomes in New Zealand adolescents.

Background: This study aimed to compare the difference in cardiorespiratory fitness between Chinese and Japanese children and adolescents. Methods: Participants comprised 9025 children and adolescents aged 7–18 years from China and Japan. Cardiorespiratory fitness (CRF) was measured by performance in the 20 m shuttle run test (20mSRT) and estimated maximal oxygen consumption (VO2max). Differences in CRF between countries were evaluated by t-tests. Centile curves for the 20mSRT and VO2max values were constructed for Chinese and Japanese children and adolescents, respectively, using the Lambda Mu and Sigma (LMS) method. Results: (1) For most of the age groups, the 20mSRT and VO2max performances among Chinese participants were lower than among Japanese participants. (2) Japanese children had the most apparent gains in P10, P50, and P90 VO2max values in primary school; however, they gradually decreased in middle school. For Chinese girls, the P10, P50, and P90 VO2max values decreased gradually with age. (3) The VO2max value among Japanese children increased; however, it decreased or remained flat among Chinese children in primary school. Conclusions: CRF among Chinese participants was lower than among Japanese participants while the VO2max value showed different trends in primary school. Effective measures should be taken to improve CRF among children and adolescents.

This study investigated physical activity and fitness of midlife and older rural women. Random-digit dialing was used to recruit 225 women (57.9 ± 5.6 years old). Self-reported activity (moderate activity, flexibility, and strength) and fitness (body composition, flexibility, strength, and estimated VO2max) were assessed. The women demonstrated low daily energy expenditure (30.74 ± 10.63 kcal · kg−1· day−1) and estimated VO2max(20.12 ± 7.81 ml · kg−1· min−1), with 51.5% reporting fair or poor health. Few women reported meeting Healthy People 2010 targets for moderate activity (43.1%), flexibility (28.9%), or strength (14.2%). When classified by estimated VO2maxinto three categories, differences were observed for body-mass index, percent body fat, sit and reach, and timed chair stands, with the poorest performance by those with low cardiorespiratory fitness. Adherence to Healthy People 2010 targets for moderate activity and strengthening was associated with higher cardiorespiratory fitness. These rural women are targets for physical activity interventions because of their sedentary behaviors and low cardiorespiratory fitness.

ABSTRACT Introduction: Metabolic Syndrome (MetS) has been associated with sedentary behavior, low levels of physical activity and of cardiorespiratory fitness. However, in adolescents the results are conflicting. Objective: To measure the association between sedentary behavior, physical activity, cardiorespiratory fitness and MetS in a representative sample of adolescents. Methods: The sample consisted of 1,035 adolescents (565 girls and 470 boys) between 12 and 20 years of age. Sedentary behavior was treated through recreational screen time, while information equivalent to physical activity was considered through the Physical Activity Questionnaire for Adolescents. The maximal oxygen uptake (VO2max), estimated through PACER performance, was used as an indicator of cardiorespiratory fitness. MetS was identified using the criteria of the International Diabetes Federation. Results: Adolescents of both sexes identified with MetS had significantly longer recreational screen time and lower VO2max than their unidentified MetS peers. Scores equivalent to the level of physical activity undertaken by adolescents identified and not identified with MetS were statistically similar. Probabilistically, adolescents with high recreational screen time and low VO2max had, respectively, 79% [OR = 1.79; 95% CI 1.10 – 2.82] and 95% [OR = 1.95; 95% CI 1.20 – 3.09] greater odds of being identified with MetS. Conclusion: The findings indicate consistent and significant associations between longer recreational screen time, low VO2max values and high prevalence of MetS, which suggests specific interventions designed to help minimize cardiometabolic risk exposure from a very early age. Level of Evidence III; Prognostic Studies - Investigating the Effect of a Patient's Characteristics on the Disease Outcome.

The purpose of this study was to evaluate the use of nonexercise (N-EX) data, specifically, the Perceived Functional Ability (PFA) and Physical Activity Rating (PA-R) questionnaires, with the treadmill walk-jog-run protocol to estimate VO2max in 12 to 17 year old boys and girls. Ninety-one participants (49 males and 42 females) took part in this study. Data were collected via PFA and PA-R questionnaires, a walk-jog-run submaximal treadmill test, and a maximal graded exercise test (GXT). Data collected included gender, age, height, weight, PFA and PA-R scores, heart rate (HR), treadmill speed, maximal treadmill grade, respiratory exchange ratio (RER), rating of perceived exertion (RPE), and VO2max. Regression analysis resulted in the development of two valid and reliable models to predict VO2max. Nonexercise and submaximal exercise test data were used to build the following model: VO2max (mL∙kg-¹∙min-¹) = 11.201 + (6.877 x Gender; 0 = female; 1 = male) + (3.573 x treadmill speed; mph) – (0.174 x kg) + (0.405 x PFA score) + (0.653 x PA-R score) + (1.019 x age). The model resulted in an R2 = 0.69 and a SEE = 5.16 mL∙kg-¹∙min-¹. Maximal exercise test data were used to build the following model: VO2max (mL∙kg-¹∙min-¹) = -3.264 + (3.359 x Gender; 0 = female; 1 = male) – (0.082 x kg) + (7.351 x treadmill speed; mph) + (1.750 x maximal treadmill grade). The model resulted in an R2 = 0.88 and a SEE = 3.16 mL∙ kg-¹∙min-¹. The cross-validation PRESS statistics for both models demonstrated minimal shrinkage in the accuracy of the regression model. The results of this study demonstrate, for the first time, that N-EX data can be used to accurately predict VO2max in youth. The submaximal and maximal exercise tests validated in this study can be used to assess cardiorespiratory fitness of youth having a wide range on interests and fitness levels. In addition, the use of PFA and PA-R questionnaires enforces initiatives to increase physical activity among youth. Both exercise tests use a self-selected treadmill speed that elicits a steady-state HR of 70% of the participants age-predicted maximal HR. The use of a self-selected walking, jogging, or running speed accommodates youth with different levels of physical fitness, motivation, and interests. The exercise test protocol presented in this study is practical for use in schools, athletic facilities, and community fitness centers. The equipment required to administer the exercise test presented in this study is limited to a treadmill and a HR monitor. Together with the use of PFA and PA-R questionnaires, the submaximal and maximal exercise tests are efficacious to coaches, fitness professionals, and physical educators in a variety of settings.

The purpose of this study was to develop a regression equation to predict VO2max based on non-exercise (N-EX) data. All participants (N = 100), aged 18-65 years old, successfully completed a maximal graded exercise test (GXT) to assess VO2max (mean ± SD; 39.96 mL∙kg-¹∙min&sup-1; ± 9.54 mL∙kg-¹∙min-¹). The N-EX data collected just before the maximal GXT included the participant's age, gender, body mass index (BMI), perceived functional ability (PFA) to walk, jog, or run given distances, and current physical activity (PA-R) level. Multiple linear regression generated the following N-EX prediction equation (R = .93, SEE = 3.45 mL∙kg-¹∙min-¹, %SEE = 8.62): VO2max (mL∙kg-¹∙min-¹) = 48.0730 + (6.1779 x gender) - (0.2463 x age) - (0.6186 x BMI) + (0.7115 x PFA) + (0.6709 x PA-R). Cross validation using PRESS (predicted residual sum of squares) statistics revealed minimal shrinkage (Rp = .91 and SEEp = 3.63 mL∙kg-¹∙min-¹); thus, this model should yield acceptable accuracy when applied to an independent sample of adults (aged 18-65) with a similar cardiorespiratory fitness level. Based on standardized β-weights the PFA variable (0.41) was the most effective at predicting VO2max followed by age (-0.34), gender (0.33), BMI (-0.27), and PA-R (0.16). This study provides a N-EX regression model that yields relatively accurate results and is a convenient way to predict VO2max in adult men and women.

O entendimento da aptidão cardiorrespiratória em crianças e jovens é hoje uma estratégia fundamental de controle da saúde em geral. No entanto, avaliar a aptidão cardiorrespiratória, de forma direta, demanda um custo financeiro alto, pessoal especializado e um tempo excessivo. Nesta perspectiva, inúmeros estudos vêm propondo testes que avaliem, de forma indireta, a aptidão cardiorrespiratória de crianças e jovens. Assim, o objetivo geral do estudo foi compreender os testes de corrida/caminhada de 6 e de 9 minutos e as relações que estes estabelecem com o VO2máx, economia de movimento (EM) e limiar anaeróbio (LA). O estudo propõe uma abordagem de validação de técnica de medida. A amostra foi do tipo não aleatória por conveniência, de corte transversal. Foram avaliados 96 sujeitos, sendo 46 do sexo masculino e 50 do sexo feminino, na faixa etária de 10 a 14 anos de idade. O estágio maturacional foi determinado de acordo com a pilosidade púbica através de Tanner (1962). Os testes de corrida/caminha de 6 e de 9 minutos foram avaliados pela maior distância alcançada no tempo determinado de cada teste. Os componentes da aptidão cardiorrespiratória foram obtidos através de um teste em esteira de carga progressiva até a exaustão, acompanhado pelo ergoespirômetro MedGraphics Cardiorespiratory Diagnostic Systems, modelo MGC/CPX-D. O valor médio de VO2 registrado durante o 4° minuto, a uma velocidade constante, foi considerado o valor de EM. VO2máx que foi obtido pelo maior valor alcançado durante o teste. O limiar ventilatório (LV) foi entendido como o VO2 expresso pelo segundo ponto de inflexão na curva de ventilação e do custo ventilatório de CO2 de cada indivíduo. Para todas as análises estatísticas foi utilizado o programa estatístico SPSS for Windows 10.0. O nível de significância adotado foi de 5%. Os principais resultados apontam que os índices alcançados no teste de 9 minutos (r= 0,632) apresentam melhor relação com o VO2máx de simples razão (ml.kg-1.min-1 ou kg-1) do que os mesmos no teste de 6 minutos (r=0,393). No entanto, o valor de r aumenta para 0,704 e 0,728 nos testes de 6 e de 9 minutos, respectivamente, quando os relacionamos com o VO2máx em expoentes alométricos (kg-0,67). Quanto ao comportamento dessas variáveis durante a puberdade, notamos incremento nos dois testes aeróbios e no VO2máx quando expresso em kg-0,67. No VO2máx (kg-1), os valores médios durante a puberdade se mantiveram estáveis. Quanto às diferenças entre os sexos, percebemos que os valores obtidos pelos meninos superam os das meninas em todas as variáveis. No entanto, percebemos que as diferenças são potencializadas quando expressamos o VO2máx em escalas alométricas (kg-0,67). No âmbito dos componentes da aptidão cardiorrespiratória constatamos que o VO2máx (kg-0,67), aliado a EM (%VO2máx) foram as variáveis que apresentaram maior poder preditivo sobre os testes aeróbios de campo analisados neste estudo, representando geralmente mais de 60% da explicação desses. Já o LV não estabeleceu relações suficientemente capazes de ser apontado como variável preponderante no desempenho dos testes de corrida/caminhada de 6 e de 9 minutos. Dessa forma, podemos concluir que os dois testes analisados são válidos para a avaliação da aptidão cardiorrespiratória se assumirmos que o VO2máx é mais bem representado pelo expoente de massa corporal kg-0,67. Além disso, constatamos que a EM, aliado à capacidade aeróbia máxima é fundamental no desempenho de testes de características aeróbias. Sendo assim, podemos sugerir a utilização do teste de corrida de 6 minutos à professores de educação física como parâmetro da aptidão cardiorrespiratória de seus alunos, pois além de ser um teste simples, de fácil compreensão e que permite sua aplicação em diferentes estruturas físicas, apresentou uma alta relação com o consumo máximo de oxigênio (kg-0,67).
The knowledge about the cardiorespiratory fitness in children and adolescents is a basic strategy of control of the health, considering that low indices of this capacity in this period of age can point important associations with hypokinetic disease in the adult age. However, to evaluate the cardiorespiratory fitness by direct methods demand a high financial cost, specialized people and excessively time. In this perspective, innumerable studies has been considering tests that measure by indirect methods the cardiorespiratory fitness of children and adolescents. Thus, the general objective of this study was to understand the of Run/walk in 6 minutes and Run/walk in 9 minutes tests and the relations that these establish with the VO2max. Moreover, we tried to identify the variables capable to determine the performance of both tests in individuals in the period of infancy and adolescence. The study considers an approach of validation of measuring technique. The sample was a not random type for convenience, with transversal cut analysis. 96 subjects had been evaluated, being 46 masculine and 50 feminine, with ages between 10 and 14 years old. The maturational status was determined by pubic hair according to Tanner (1962). The tests of Run/walk in 6 minutes and Run/walk in 9 minutes had been understood by the biggest distance reached in the definitive time of each test. The components of the cardiorespiratory fitness were gotten through a gradual load test in treadmill until the exhaustion, measured through a gas meter model (MedGraphics Cardiorespiratory Diagnostic Systems – MGC/CPX-D). The average value of VO2 registered during the 4th minute, in a constant speed, was considered the value of movement economy (ME). The VO2max was gotten by the highest value reached during the test. The ventilatory threshold was understood as the VO2 expressed for the second point of inflection in the curve of ventilation and CO2 ventilatory cost for each individual. For all the statistical analyses the statistical program SPSS for Windows 10.0 was used. The level of significance adopted for all the analyses was of 5%. The main results point that the indices reached in the test of 9 minutes (r = 0,632) present better relationship with the VO2max of simple reason (ml.kg-1.min-1 or kg-1) than the same ones in the test of 6 minutes (r=0,393). However, the value of r increases for 0,704 and 0,728 in the tests of 6 and 9 minutes, respectively, when we relate them with the VO2max in allometric exponents (kg-0,67). About the behavior of these variables during the puberty, we notice an increment in the two aerobic tests and in the VO2max expressed in kg-0,67. In the VO2max (kg-1), the average values during the puberty remained steady. About the differences between sexes, we perceive that the values gotten for the boys surpass of the girls in all variables. However, we perceive that the differences are powered when we express the VO2max in allometric scales (kg-0,67). About the components of the cardiorespiratory fitness, we evidence that the VO2max (kg-0,67), ally to the ME (%VO2max) had been the variables that had presented greater predictive power on the field aerobic tests analyzed in this study, representing generally more than 60% of the explanation of these. However, the ventilatory threshold did not establish relationships capable enough to be pointed as the preponderant variable in the performance of Run/walk in 6 minutes and Run/walk in 9 minutes tests. This way, we can conclude that the two analyzed tests are valid for the evaluation of the cardiorespiratory fitness if we assume that the VO2max is better represented by the allometric scales. Moreover, we evidence that the movement economy, ally to the maximum aerobic capacity is basic in the performance of aerobic characteristics tests. Thus, we can suggest the use of the Run/walk in 6 minutes test to any physical education teacher as a parameter of the cardiorespiratory fitness of his students, therefore it is a simple test, of easy understanding, that allows its application in different physical structures and it shows excellent relationship with the maximum oxygen consumption (kg-0,67).

Syfte och frågeställningar. Syftet med studien är att, hos äldre personer, över 65 år, samt hos yngre vuxna, mellan 20-30 år, jämföra syreupptagningsförmågan med två olika metoder, fem-minuterspyramidtest (5MPT) samt VO2max-test på löpband. Vid båda mätmetoderna används direkt syrgasmätning. Metod. Totalt deltog 36 personer i studien, varav 17 äldre personer 65 till 85 år (9 kvinnor och 8 män) samt 19 yngre med en ålder mellan 20 till 35 år (10 kvinnor och 9 män). Deltagarnas syreupptagningsförmåga mättes under 5MPT vid två tillfällen som sedan jämfördes med VO2max mätt via ett maximalt test på löpband vid ett tillfälle. Således utfördes sammanlagt tre mätningar med direkt syrgasmätning, via andningsmask, under ett maximalt löpbandstest samt under två separata tester av 5MPT med minst 48 timmar mellan varje testtillfälle. Utandningsluften analyserades sedan, vid 5MPT för alla, via det trådlösa portabla systemet Jaeger Oxycon Mobile och vid test på löpband för testgruppen med yngre deltagare. För den testgrupp med äldre deltagare användes, vid testet på löpband, den fasta on-line-utrustningen Jaeger Oxycon Pro som är en liknande mätmetod för syreupptag. 5MPT är ett fem minuter långt test där individen från golvnivå, med högsta möjliga tempo, förflyttar sig fram och tillbaka på en 5,50 meter lång sträcka med en centralt placerad trappramp som är pyramidformad och med en högsta central höjd på 0,62 meter. Resultat. Det primära fyndet i studien var att en stark signifikant korrelation (r = 0,99) visade sig mellan direkt uppmätt VO2max under maximalt test på löpband gentemot syreupptagningsförmågan vid 5MPT då båda åldersgrupperna var sammanslagna, uppmätt i l·min–1. Slutsats. Då det i undersökningen visades en stark signifikant korrelation mellan direkt uppmätt VO2max vid 5MPT och ett maximalt test på löpband i l·min–1 för äldre och yngre vuxna ger det indikationer på att 5MPT kan används som en tillförlitlig metod vid undersökning och uppföljning av en persons aeroba förmåga. Fyndet kan vara av värde då det genom mindre kostsamma och enklare metoder går att få ett mått på en persons hälsa i form av aerob kapacitet, vilket är betydelsefullt ur flera hälsoaspekter på individ- och samhällsnivå.
Aim. The purpose of the study was to investigate the results and correlation between oxygen uptake levels (VO2max) at five-minute pyramid test (5MPT) against maximal oxygen uptake test (VO2max) on a treadmill test, both measured by direct oxygen measurement, in elderly people over 65 years and younger adults aged 20-30 years. Method. A total of 36 people participated in the study, 17 elderly people aged between 65 to 85 years (9 women and 8 men) and 19 younger adults aged between 20 to 35 years (10 women and 9 men). The participants' oxygen uptake was measured twice during 5MPT and then compared with VO2max measured by a maximal treadmill test at one occasion. Thus a total of three measurements with direct oxygen measurement, via the breathing mask, during a maximum treadmill test and two separate tests of 5MPT with at least 48 hours between each test. The exhaled air was analyzed at 5MPT for all, through the wireless portable system Jaeger Oxycon Mobile and also during the test on treadmill for the test group with younger participants. The test group of older participants, got their exhaled air analyzed through a stationary on-line equipment Jaeger Oxycon Pro instead of the portable system which is a similar reliable method to measure VO2max. 5MPT is a five minute test where the subjects from floor level, with the highest possible speed, moves back and forth at a measured distance of 5.50 meter with a central staircase ramp, which is pyramid-shaped, with a maximum center height of 0.62 meters. Results. The main finding of the study was that there was a strong significant correlation (r = 0.99) between directly measured VO2max during a maximum treadmill test compared to oxygen uptake at 5MPT when both the elderly people and the younger adults were combined, measured in l·min–1. Conclusion. The study showed a strong significant correlation between directly measured VO2max at 5MPT and a maximal treadmill testing l·min–1 for older and younger adults. This indicates that 5MPT can be used as a reliable method for investigation and monitoring a person’s aerobic capacity. This finding may be of value because it shows that less expensive and easier methods can be used to measure a person's health in terms of aerobic capacity, which is important from several aspects of health at both the individual and society level.

The 20 Metre Multistage Shuttle Run Test (20 MST) was modified for application to ice-sports, more specifically for ice-hockey and figure-skating. Seventy two participants in ice-sports served as the total subject group. Subjects included in the study were National and Provincial standard male ice-hockey subjects (n=67) and female figure skaters (n=5) participating in the Gauteng area of South Africa (altitude of 1497 metres above sea level and barometric pressure of 655 mmHg). The mean age for the total group was 17.44±1.33 years. The research methodology entailed a repeated measures design to determine: a) velocity of motion on-ice vs. over-ground; b) energy expenditure on-ice vs. over-ground; and c) mechanical efficiency on-ice vs. over-ground. The mean velocity of motion measured over three distances (0 to 20, 0 to 30 and 0 to 40 m) indicated a significantly (p≤0.05) faster velocity on-ice (5.99±0.72 m/s) versus over-ground (5.75±0.63 m/s). The corresponding mean time-lapsed on-ice/over-ground ratio was 0.97±0.11. Differences in mean energy expenditure whilst performing the original 20 MST over-ground as opposed to on-ice were measured at low (at 4 minutes of exercise and 10 km/h), intermediate (after 8 minutes of exercise and 12 km/h), and high intensity (after 12 min of exercise and 14 km/h). The mean of the three indicated a significantly (p≤0.05) higher energy expenditure over-ground (14.04±4.86 kcal/min) as apposed to on-ice (10.51±2.95 kcal/min). The mean energy expenditure ratio for the three different intensities on-ice vs. over-ground was 0.74±0.21. Similarly, the mechanical efficiency index over-ground (4.92±0.59) was found to be significantly (p≤0.001) poorer than on-ice (6.83±1.49). The mean mechanical efficiency ratio over-ground/over-ice was 0.74±0.13. Subsequently, based on the above results, the 20 MST was modified by: a) adapting (increasing) the velocity of motion required for each level of the test (distance of 20 m per shuttle); and b) establishing the reliability and validity of the modified 20 MST for use on-ice. The adapted 20 Metre Multistage Shuttle Skating Test (the modified (skating) 20 MST) started at a velocity of 2.8 m/s (10.1 km/h) and permitted 7.1 seconds to complete each shuttle for the first level of the test, which then decreased progressively at each level. This was based on an over-all variable-derived on-ice to over ground ratio of 0.84. Test-retest, on-ice reliability measures (n=15) for predicted VO2max (49.5±8.37 vs. 49.29±7.95 ml/kg/min) showed a highly significant (p£0.001) consistency (r=0.87). Similarly test-retest concurrent validity measures (n=10) for predicted VO2max over-ground with the original 20 MST (48.09±6.25 ml/kg/min) as designed by Léger and Lambert (1982) versus on-ice values with the adapted on-ice 20 MST (49.98±7.23 ml/kg/min), showed a very significant (p£0.01) correlation of 0.73 between the two tests. In conclusion the original 20 MST, as designed by Léger and Lambert (1982) for over-ground, proved inappropriate for use on-ice. Modification of the starting velocity as well as a progressive increase in velocity for all subsequent stages renders the modified 20 MST for ice-sports a reliable and valid test for cardiorespiratory fitness (VO2max), with surface-specific utility. The 20 Metre Multistage Shuttle Run Test (20 MST) was modified for application to ice-sports, more specifically for ice-hockey and figure-skating. Seventy two participants in ice-sports served as the total subject group. Subjects included in the study were National and Provincial standard male ice-hockey subjects (n=67) and female figure skaters (n=5) participating in the Gauteng area of South Africa (altitude of 1497 metres above sea level and barometric pressure of 655 mmHg). The mean age for the total group was 17.44±1.33 years. The research methodology entailed a repeated measures design to determine: a) velocity of motion on-ice vs. over-ground; b) energy expenditure on-ice vs. over-ground; and c) mechanical efficiency on-ice vs. over-ground. The mean velocity of motion measured over three distances (0 to 20, 0 to 30 and 0 to 40 m) indicated a significantly (p≤0.05) faster velocity on-ice (5.99±0.72 m/s) versus over-ground (5.75±0.63 m/s). The corresponding mean time-lapsed on-ice/over-ground ratio was 0.97±0.11. Differences in mean energy expenditure whilst performing the original 20 MST over-ground as opposed to on-ice were measured at low (at 4 minutes of exercise and 10 km/h), intermediate (after 8 minutes of exercise and 12 km/h), and high intensity (after 12 min of exercise and 14 km/h). The mean of the three indicated a significantly (p≤0.05) higher energy expenditure over-ground (14.04±4.86 kcal/min) as apposed to on-ice (10.51±2.95 kcal/min). The mean energy expenditure ratio for the three different intensities on-ice vs. over-ground was 0.74±0.21. Similarly, the mechanical efficiency index over-ground (4.92±0.59) was found to be significantly (p≤0.001) poorer than on-ice (6.83±1.49). The mean mechanical efficiency ratio over-ground/over-ice was 0.74±0.13. Subsequently, based on the above results, the 20 MST was modified by: a) adapting (increasing) the velocity of motion required for each level of the test (distance of 20 m per shuttle); and b) establishing the reliability and validity of the modified 20 MST for use on-ice. The adapted 20 Metre Multistage Shuttle Skating Test (the modified (skating) 20 MST) started at a velocity of 2.8 m/s (10.1 km/h) and permitted 7.1 seconds to complete each shuttle for the first level of the test, which then decreased progressively at each level. This was based on an over-all variable-derived on-ice to over ground ratio of 0.84. Test-retest, on-ice reliability measures (n=15) for predicted VO2max (49.5±8.37 vs. 49.29±7.95 ml/kg/min) showed a highly significant (p£0.001) consistency (r=0.87). Similarly test-retest concurrent validity measures (n=10) for predicted VO2max over-ground with the original 20 MST (48.09±6.25 ml/kg/min) as designed by Léger and Lambert (1982) versus on-ice values with the adapted on-ice 20 MST (49.98±7.23 ml/kg/min), showed a very significant (p£0.01) correlation of 0.73 between the two tests. In conclusion the original 20 MST, as designed by Léger and Lambert (1982) for over-ground, proved inappropriate for use on-ice. Modification of the starting velocity as well as a progressive increase in velocity for all subsequent stages renders the modified 20 MST for ice-sports a reliable and valid test for cardiorespiratory fitness (VO2max), with surface-specific utility.
Dissertation (MA (Human Movement Science))--University of Pretoria, 2005.
Biokinetics, Sport and Leisure Sciences
unrestricted

ABSTRACT Background: Cardiorespiratory fitness essential to prevent the risk cardiovascular disease. This study aimed to determine the relative effectiveness of Steady State Cardio (SSC) and High-Intensity Interval Training (HIIT) on cardiorespiratory fitness in the early adult age group. Subjects and Method: This was a randomized control trial conducted at the School of Health Polytechnics, Surakarta, from October to November, 2019. A total sample 45 students was divided into 2 groups: (1) SSC group and (2) HIIT group. The dependent variable was cardiorespiratory fitness. The independent variables were SSC and HIIT. The measuring instrument was a multi-stage fitness involving a 20 meter long run. The results were converted into VO2max level. The data were analyzed by Mann Whitney. Results: After the intervention, the VO2max level was higher in the HIIT group (Mean= 24.28; SD= 5.42) than the SSC group (Mean= 21.66; SD= 6.99), but it was statistically non-significant (p= 0.503). Conclusion: Steady State Cardio and High Intensity Interval Training have comparable effect on cardiorespiratory fitness. Keywords: high intensity interval training, steady state cardio, cardiorespiratory fitness, VO2max Correspondence: Mei Kusumaningtyas. School of Health Polytechnics, Surakarta. Jl. Adi Sumarmo, Tohudan, Colomadu, Karanganyar, Indonesia. Email: meikusumaningtyas@gmail.com. Mobile: 085725646444 DOI: https://doi.org/10.26911/the7thicph.05.08

Purpose: Breast cancer patients are at increased risk of developing comorbidities such as lymphedema, sarcopenia, osteoporosis and cardiovascular disease after breast cancer treatment. These complications contribute to a decrease in quality of life, cardiorespiratory fitness and muscle strength. Regular and long-term physical activity is an effective non-pharmacological strategy that can improve physical, psychological and social outcomes. The aim of our research was to evaluate the effect of various modes of an exercise intervention on physical performance, body composition, depression and autonomic nervous system in breast cancer survivors. Methods: 16 women after surgery with hormonal treatment enter the research. Thirteen of them completed the controlled, quasi-experimental study (54 ± 9 yrs, 164cm ± 6cm, 72 ± 12kg) and were divided into 3 groups according to their place of living: trained under supervision (n=5) (SUPERV), trained at home without supervision by videos (n=7) (HOME) and with no prescribed physical activity (n=4) (CON). Exercise intervention lasted 3 months and comprised of 60 min training units 3 × week (aerobic with resistant exercise in a 2 : 1 mode combined with regular weekly yoga and breathing exercises). The exercise intensity was set individually at 65–75% of HRR based on spiroergometry and was continuously controlled by heart rate monitors. The same principles applied to the HOME group, which, in addition to heart rate monitors, recorded frequency, length, HRmax, HRavg, and Borg scale of intensity perception. VO2max, BMI, fat mass, depression level (Beck’s depression inventory) and the power of the autonomic nervous system (total power and sympatho-vagal balance) were analyzed. For data evaluation we used descriptive statistics and Cohens d effect size. Results: 3 women dropped out of research because of medical reason. In all groups VO2max values increased. The largest increase in VO2max values was in SUPERV group by 36%, in HOME group by 20% and in CON group by 2%. Body weight decreased for groups SUPERV (˗1.2 kg) and CON (-0.1kg), for HOME group there was an increase (+0.2 kg). Body mass index decreased for SUPERV group (-0.4), for HOME and CON it increased (both +0.1). Total power decreased in SUPERV (-0.6) and HOME group (-0.2), in CON has not changed. The same results were achieved by the sympatho-vagal balance, only the CON group increased. Values from Beck’s depression inventory decreased for all groups, most for CON group. Conclusion: A 3-months of supervised and controlled exercise had a significant effect on physical fitness and body composition in comparison with non-supervised home-based physical intervention. Our results indicate that it is strongly advisable to apply a supervised exercise program to induce positive physiological changes in breast cancer survivors as part of aftercare.