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1

Clark, Kenneth P. "Determinants of Top Speed Sprinting: Minimum Requirements for Maximum Velocity." Applied Sciences 12, no. 16 (August 19, 2022): 8289. http://dx.doi.org/10.3390/app12168289.

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Анотація:
Faster top sprinting speeds require shorter ground contact times, larger vertical forces, and greater thigh angular velocities and accelerations. Here, a framework using fundamental kinematic and kinetic relationships is presented that explores the effect of body dimensions on these mechanical determinants of sprinting performance. The analysis is applied to three hypothetical runners of different leg lengths to illustrate how these mechanical determinants of speed vary with body dimensions. Specific attention is focused on how the following variables scale with leg length and top speed: ground contact time, step rate, step length, ratio of step length to leg length, ratio of vertical force to body weight, total thigh range of motion, average thigh angular velocity, and maximum thigh angular acceleration. The analysis highlights the inherent biological tradeoffs that interplay to govern the optimal dimensions for sprinting speed and underscores that accounting for leg length may facilitate interpretation in future investigations examining the relationship between these mechanical variables and top speed. Furthermore, for athletes with given body dimensions and sprinting performance goals, this framework could help to establish the minimum requirements for maximum velocity.
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2

Mattes, Klaus, Stefanie Wolff, and Shahab Alizadeh. "Kinematic Stride Characteristics of Maximal Sprint Running of Elite Sprinters – Verification of the “Swing-Pull Technique”." Journal of Human Kinetics 77, no. 1 (January 30, 2021): 15–24. http://dx.doi.org/10.2478/hukin-2021-0008.

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Abstract Maximum sprinting speed constitutes an optimum relation between the stride length and the step rate in addition to an appropriate sprinting technique. The kinematics of the sprint step at maximum sprinting speed have already been examined in numerous studies, without reaching a consensus. The aim of this study was to analyze the relationship between maximum sprinting speed and the stride kinematics based on the “Swing-Pull Technique”. German elite sprinters (N = 26, body height = 182 ± 6 cm, leg length 93.8 ± 4.1 cm) were tested while performing a 30-meter flying sprint at maximum sprinting speed. The relationship between sprinting speed and kinematic variables was determined via Pearson correlation. Sprinting speed (10.1 – 11.3 m/s) correlated with stride length (r = 0.53), ground contact time (r = -0.53) and variables from the technique model: the knee angle at the end of the knee lift swing (r = 0.40), the maximum knee angle prior to backswing (r = 0.40), the hip extension angle velocity (r = 0.63), and vertical foot velocity (r = 0.77) during pre-support, the ankle angle at the take-on (r = -0.43), knee flexion (r = -0.54), and knee extension (r = -0.47) during support. The results indicate that greater stride length, smaller contact time, and the mentioned kinematic step characteristics are relevant for the production of maximum sprinting speed in athletes at an intermediate to advanced performance level. The association of sprinting speed and these features should primarily be taken into account in conditioning and technical training.
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3

Waters, Amy, Elissa Phillips, Derek Panchuk, and Andrew Dawson. "Coach and Biomechanist Experiential Knowledge of Maximum Velocity Sprinting Technique." International Sport Coaching Journal 6, no. 2 (May 2019): 172–86. http://dx.doi.org/10.1123/iscj.2018-0009.

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4

Carlos-Vivas, Jorge, Elena Marín-Cascales, Tomás T. Freitas, Jorge Perez-Gomez, and Pedro E. Alcaraz. "Force-Velocity-Power Profiling During Weighted-Vest Sprinting in Soccer." International Journal of Sports Physiology and Performance 14, no. 6 (July 1, 2019): 747–56. http://dx.doi.org/10.1123/ijspp.2018-0490.

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Анотація:
Purpose: To describe the load–velocity relationship and the effects of increasing loads on spatiotemporal and derived kinetic variables of sprinting using weighted vests (WV) in soccer players and determining the load that maximizes power output. Methods: A total of 23 soccer players (age 20.8 [1.5] y) performed 10 maximal 30-m sprints wearing a WV with 5 different loads (0%, 10%, 20%, 30%, and 40% body mass [BM]). Sprint velocity and time were collected using a radar device and wireless photocells. Mechanical outputs were computed using a recently developed valid and reliable field method that estimates the step-averaged ground-reaction forces during overground sprint acceleration from anthropometric and spatiotemporal data. Raw velocity–time data were fitted by an exponential function and used to calculate the net horizontal ground-reaction forces and horizontal power output. Individual linear force–velocity relationships were then extrapolated to calculate the theoretical maximum horizontal force (F0) and velocity and the ratio of force application (proportion of the total force production that is directed forward at sprint start). Results: Magnitude-based inferences showed an almost certain decrease in F0 (effect size = 0.78–3.35), maximum power output (effect size = 0.78–3.81), and maximum ratio of force (effect size = 0.82–3.87) as the load increased. The greatest changes occurred with loads heavier than 20% BM, especially in ratio of force. In addition, the maximum power was achieved under unloaded conditions. Conclusions: Increasing load in WV sprinting affects spatiotemporal and kinetic variables. The greatest change in ratio of force happened with loads heavier than 20% BM. Thus, the authors recommend the use of loads ≤20% BM for WV sprinting.
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5

Rumpf, Michael C., John B. Cronin, Jonathan Oliver, and Michael Hughes. "Kinematics and Kinetics of Maximum Running Speed in Youth Across Maturity." Pediatric Exercise Science 27, no. 2 (May 2015): 277–84. http://dx.doi.org/10.1123/pes.2014-0064.

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Sprinting is an important physical capacity and the development of sprint ability can take place throughout the athlete’s growth. The purpose of this study therefore was to determine if the kinematics and kinetics associated with maximum sprint velocity differs in male youth participants of different maturity status (pre, mid- and postpeak height velocity (PHV)) and if maximum sprint velocity is determined by age, maturity or individual body size measurement. Participants (n = 74) sprinted over 30 meters on a nonmotorized treadmill and the fastest four consecutive steps were analyzed. Pre-PHV participants were found to differ significantly (p < .05) to mid- and post-PHV participants in speed, step length, step frequency, vertical and horizontal force, and horizontal power (~8-78%). However, only relative vertical force and speed differed significantly between mid and post-PHV groups. The greatest average percent change in kinetics and kinematics was observed from pre- to mid-PHV (37.8%) compared with mid- to post- PHV groups (11.6%). When maturity offset was entered as a covariate, there was no significant difference in velocity between the three groups. However, all groups were significantly different from each other when age was chosen as the covariate. The two best predictors of maximal velocity within each maturity group were power and horizontal force (R2 = 97−99%) indicating the importance of horizontal force application while sprinting. Finally, maturity explained 83% of maximal velocity across all groups.
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6

Shah, Sunnan, Kieran Collins, and Lewis J. Macgregor. "The Influence of Weekly Sprint Volume and Maximal Velocity Exposures on Eccentric Hamstring Strength in Professional Football Players." Sports 10, no. 8 (August 19, 2022): 125. http://dx.doi.org/10.3390/sports10080125.

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Background: Hamstring strains are the most common moderate-major severity injuries in football. The majority of hamstring injuries occur during sprinting, with low eccentric hamstring strength being associated with an elevated risk. Objective: To examine the relationship between sprinting and eccentric hamstring strength by monitoring total weekly sprint distance and weekly efforts > 90% and >95% of maximum velocity. Methods: Fifty-eight professional male footballers were observed over one-and-a-half seasons. Players’ running was monitored during training and matches using GPS, and eccentric hamstring strength was measured weekly. Results: Weekly sprint distance (ρ = −0.13, p < 0.01) and weekly efforts >90% of maximum velocity (ρ = −0.08, p = 0.01) both displayed significant inverse relationships with the percentage change in eccentric hamstring strength; weekly efforts >95% of maximum velocity showed no relationship with hamstring strength (ρ = −0.02, p = 0.45). Only weekly efforts >90% of maximum velocity significantly influenced the mean percentage change in eccentric hamstring force, F(3,58) = 3.71, p = 0.01, with significant differences occurring when comparing 7–8 sprint efforts with 0–2 efforts (0.11%, p = 0.03) and 5–6 efforts (0.12%, p = 0.03). Conclusions: Eccentric hamstring strength levels significantly decrease when 7–8 weekly sprint efforts are completed at >90% of maximum velocity. Monitoring weekly sprint loading at velocities > 90% of maximum velocity may be valuable to help to reduce the risk of hamstring injuries in professional football.
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7

Osterwald, Katja M., David T. Kelly, Thomas M. Comyns, and Ciarán Ó. Catháin. "Resisted Sled Sprint Kinematics: The Acute Effect of Load and Sporting Population." Sports 9, no. 10 (September 30, 2021): 137. http://dx.doi.org/10.3390/sports9100137.

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In this study, we assessed the acute kinematic effects of different sled load conditions (unloaded and at 10%, 20%, 30% decrement from maximum velocity (Vdec)) in different sporting populations. It is well-known that an athlete’s kinematics change with increasing sled load. However, to our knowledge, the relationship between the different loads in resisted sled sprinting (RSS) and kinematic characteristics is unknown. Thirty-three athletes (sprinters n = 10; team sport athletes n = 23) performed a familiarization session (day 1), and 12 sprints at different loads (day 2) over a distance of 40 m. Sprint time and average velocity were measured. Sagittal-plane high-speed video data was recorded for early acceleration and maximum velocity phase and joint angles computed. Loading introduced significant changes to hip, knee, ankle, and trunk angle for touch-down and toe-off for the acceleration and maximum velocity phase (p < 0.05). Knee, hip, and ankle angles became more flexed with increasing load for all groups and trunk lean increased linearly with increasing loading conditions. The results of this study provide coaches with important information that may influence how RSS is employed as a training tool to improve sprint performance for acceleration and maximal velocity running and that prescription may not change based on sporting population, as there were only minimal differences observed between groups. The trunk lean increase was related to the heavy loads and appeared to prevent athletes to reach mechanics that were truly reflective of maximum velocity sprinting. Lighter loads seem to be more adequate to not provoke changes in maxV kinematics. However, heavy loading extended the distance over which it is possible to train acceleration.
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8

Lam, Wing-Kai, Winson Chiu-Chun Lee, Wei Min Lee, Christina Zong-Hao Ma, and Pui Wah Kong. "Segmented Forefoot Plate in Basketball Footwear: Does it Influence Performance and Foot Joint Kinematics and Kinetics?" Journal of Applied Biomechanics 34, no. 1 (February 1, 2018): 31–38. http://dx.doi.org/10.1123/jab.2017-0044.

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This study examined the effects of shoes’ segmented forefoot stiffness on athletic performance and ankle and metatarsophalangeal joint kinematics and kinetics in basketball movements. Seventeen university basketball players performed running vertical jumps and 5-m sprints at maximum effort with 3 basketball shoes of various forefoot plate conditions (medial plate, medial + lateral plates, and no-plate control). One-way repeated measures ANOVAs were used to examine the differences in athletic performance, joint kinematics, and joint kinetics among the 3 footwear conditions (α = .05). Results indicated that participants wearing medial + lateral plates shoes demonstrated 2.9% higher jump height than those wearing control shoes (P = .02), but there was no significant differences between medial plate and control shoes (P > .05). Medial plate shoes produced greater maximum plantar flexion velocity than the medial + lateral plates shoes (P < .05) during sprinting. There were no significant differences in sprint time. These findings implied that inserting plates spanning both the medial and lateral aspects of the forefoot could enhance jumping, but not sprinting performances. The use of a medial plate alone, although induced greater plantar flexion velocity at the metatarsophalangeal joint during sprinting, was not effective in improving jump heights or sprint times.
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9

Alcaraz, P., J. Palao, J. Elvira, and N. Linthorne. "EFFECTS OF A SAND RUNNING SURFACE ON THE KINEMATICS OF SPRINTING AT MAXIMUM VELOCITY." Biology of Sport 28, no. 2 (May 12, 2011): 95–100. http://dx.doi.org/10.5604/942737.

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10

Miller, Ross H., Brian R. Umberger, and Graham E. Caldwell. "Sensitivity of maximum sprinting speed to characteristic parameters of the muscle force–velocity relationship." Journal of Biomechanics 45, no. 8 (May 2012): 1406–13. http://dx.doi.org/10.1016/j.jbiomech.2012.02.024.

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11

Yu, Jiabin, Yuliang Sun, Chen Yang, Donghai Wang, Keyi Yin, Walter Herzog, and Yu Liu. "Biomechanical Insights Into Differences Between the Mid-Acceleration and Maximum Velocity Phases of Sprinting." Journal of Strength and Conditioning Research 30, no. 7 (July 2016): 1906–16. http://dx.doi.org/10.1519/jsc.0000000000001278.

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12

Chen, Wenjia, Biyu Zhang, Tseching Liang, and Zehao Tong. "BUILDING A PROFILE OF SPECIFIC FITNESS INDICES FOR MALE TEENAGE CHINESE SPRINTERS." Revista Brasileira de Medicina do Esporte 28, no. 4 (August 2022): 320–25. http://dx.doi.org/10.1590/1517-8692202228042021_0166.

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ABSTRACT Objectives: This study aimed to construct a profile of specific fitness indices for male teenage sprinters on the Chinese National Team to provide sprinting fitness assessments for teenage training. Material and Methods: 229 male teenage sprinters at the same level were recruited to participate in this test for the indices. The t- and Kruskal-Wallis tests were conducted for the first selection of fitness indices. In the second selection, principal components analysis was applied to select common factors with greater characteristic values. The fitness indices chosen were height, leg length, measurement B (ankle circumference/heel length×100%) and measurement A (thigh circumference/leg length×100%), hemoglobin, 60m sprint time, 100m sprint time, countermovement jump (CMJ), maximum countermovement jump velocity, CMJ flight time, CMJ maximum force, and CMJ force. Results: Thirteen indices were chosen for the specific fitness of male teenage Chinese male sprinters with 3 general categories and 9 subcategories. The weight of each fitness index was confirmed and used to construct a standard fitness assessment scale. Conclusion: Anthropometric indices indicate the athlete’s innate limits in the structure of the sprinting motion. Physiological indices indicate the athlete’s potential to expend energy and recover in a short time. Motor indices indicate the athlete’s maximum sprinting ability, lower limb reaction strength, power, and maximum strength. Level of evidence II, Diagnostic studies - Investigation of a diagnostic test.
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13

Matusiński, Aleksander, Artur Gołaś, Adam Zając, Magdalena Nitychoruk, and Adam Maszczyk. "Optimizing the load for peak power and peak velocity development during resisted sprinting." Physical Activity Review 9, no. 1 (2021): 128–34. http://dx.doi.org/10.16926/par.2021.09.15.

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Introduction: Resistance towing is perhaps the most specific form of developing strength and power in muscles involved directly during the start, acceleration and at maximum speed. Resisted sprint training may involve towing a sled which provides an overload through the friction between the sled and ground surface or a modern advanced training device which uses drag technology to provide fully controlled resistance during the movement, such as the 1080 Sprint. The main objective of the study was to evaluate the optimal loading for the development of power in the engine assisted drag technology system SPRINT 1080. Material and methods: We evaluated the changes in running velocity and the generated force and power during resisted sprints over 30m with a load of 1, 3, 6, 9, 12 and 15 kg. Seven male sprinters with national and international experience participated in the study. Their average age, body mass and body height were 22.2 ± 2.4 years, 77.43 ± 4.63 kg, and 178.6 ± 3.2 cm, respectively. All athletes performed six 30 m sprints with 5 min rest intervals in between. The first sprint was performed without additional resistance, while the remaining 5 were performed in an random order with additional resistance of 3, 6, 9, 12 and 15 kg. After receiving a verbal signal, the participant started at will from a semi crouched position. During the resisted sprint trials, the time [s] and the following variables were recorded in peak values: power output [W], generated force [N], and sprinting velocity [m/s]. Results: Our results show that loading with 6 kg decreased sprinting velocity by 9.37% while the generated horizontal power increased by 31,32%. The 6 kg loading on the Sprint 1080device corresponded to 8% body mass, yet as mentioned before the baseline results were not fully free sprinting as the tested athletes reached velocities 0.5-0.6 m/s greater without the harness. Conclusion: Taking into account this fact, our results seem to confirm previous findings, that external loads between 8 and 13% may be optimal for improving power and sprinting speed at the same time.
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14

Janjic, Natasa, Darko Kapor, Dragan Doder, Aleksandar Petrovic, and Radoslava Doder. "A Model for Determining the Effect of the Wind Velocity on 100 M Sprinting Performance." Journal of Human Kinetics 57, no. 1 (June 22, 2017): 159–67. http://dx.doi.org/10.1515/hukin-2017-0057.

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AbstractThis paper introduces an equation for determining instantaneous and final velocity of a sprinter in a 100 m run completed with a wind resistance ranging from 0.1 to 4.5 m/s. The validity of the equation was verified using the data of three world class sprinters: Carl Lewis, Maurice Green, and Usain Bolt. For the given constant wind velocity with the values + 0.9 and + 1.1 m/s, the wind contribution to the change of sprinter velocity was the same for the maximum as well as for the final velocity. This study assessed how the effect of the wind velocity influenced the change of sprinting velocity. The analysis led to the conclusion that the official limit of safely neglecting the wind influence could be chosen as 1 m/s instead of 2 m/s, if the velocity were presented using three, instead of two decimal digits. This implies that wind velocity should be rounded off to two decimal places instead of the present practice of one decimal place. In particular, the results indicated that the influence of wind on the change of sprinting velocity in the range of up to 2 m/s and was of order of magnitude of 10-3 m/s. This proves that the IAAF Competition Rules correctly neglect the influence of the wind with regard to such velocities. However, for the wind velocity over 2 m/s, the wind influence is of order 10-2 m/s and cannot be neglected.
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15

Chmura, Paweł, José M. Oliva-Lozano, José M. Muyor, Marcin Andrzejewski, Jan Chmura, Sławomir Czarniecki, Edward Kowalczuk, Andrzej Rokita, and Marek Konefał. "Physical Performance Indicators and Team Success in the German Soccer League." Journal of Human Kinetics 83, no. 1 (August 23, 2022): 257–65. http://dx.doi.org/10.2478/hukin-2022-0099.

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Abstract The aims of this study were (1) to determine the match running performance required by different teams based on their final ranking position and (2) to analyze the association between match running performance variables and team success at the end of the season. A total of 1,224 match observations from professional soccer teams competing during two consecutive seasons in the German Bundesliga were analyzed. In addition, the final league ranking position and the total of points obtained by each team at the end of the season were registered for the analysis of the association between team success and match running performance. The main findings were that high ranked teams covered the greatest total distance with ball possession, sprinting distance with ball possession, and completed the greatest number of sprinting actions with ball possession and maximal velocity. Moreover, total distance covered with possession of the ball and maximal velocity were the most important variables to predict the total of points obtained at the end of the season. Specifically, the relative contribution of total distance covered with ball possession to the total of points obtained was greater than maximal velocity. Training programs for professional soccer players should be focused on improving the sprint capacity and running with possession of the ball (e.g., transitional tasks and small-sided games). Moreover, this has implications for injury prevention, physical, psychological, and technical-tactical training since today’s soccer requires players to engage in repeated high-intensity actions, reach maximum speeds above 9 m/s, and develop technical-tactical coordination when running with the ball.
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16

Fernández-Galván, Luis Miguel, Pablo Prieto-González, Jorge Sánchez-Infante, Pedro Jiménez-Reyes, and Arturo Casado. "The Post-Activation Potentiation Effects on Sprinting Abilities in Junior Tennis Players." International Journal of Environmental Research and Public Health 19, no. 4 (February 13, 2022): 2080. http://dx.doi.org/10.3390/ijerph19042080.

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Objective: This study aimed to compare the acute effects of a full squat (SQ) or hip thrust (HT) with two different loading intensities (60% and 85% 1 RM) on sprint ability in junior male tennis players. Methods: Nineteen tennis players were included in this research. They underwent four different experimental conditions: HT at 60% 1 RM, HT at 85% 1 RM, SQ at 60% 1 RM, or SQ at 85%. The force–velocity (F–V) profile was used to assess tennis players’ sprint acceleration ability before and after applying the conditioning stimulus. The variables registered were as follows: 5 m test (5 m), 10 m test (10 m), maximum theoretical force (F0), maximum power (Pmax), and the maximal ratio of horizontal-to-resultant force (RFpeak). Results: Significant improvements in 5 m, Pmax, and RFpeak were observed when the conditioning stimulus was performing one set of seven reps of HT at 60% 1 RM. When the activation protocol was one set of seven reps of SQ at 60% 1 RM, significant improvements in 5 m, 10 m, F0, Pmax (N), and RFpeak were detected. Additionally, performing one set of three reps of SQ at 85% 1 RM as an activation protocol provided significant improvements in F0. Conclusion: The use of HT and SQ with a load of 60% 1 RM improved the sprint F–V profile components related to the acceleration phase of the sprint in junior tennis players. Using intensity loads of 85% 1 RM is not adequate to increase acute sprint performance in this population. HT presents a higher transferability to sprinting in the first 5 m of sprinting, whereas SQ provides acute improvements in different sprinting phases.
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17

Alcaraz, Pedro E., José M. Palao, José L. L. Elvira, and Nicholas P. Linthorne. "Effects of Three Types of Resisted Sprint Training Devices on the Kinematics of Sprinting at Maximum Velocity." Journal of Strength and Conditioning Research 22, no. 3 (May 2008): 890–97. http://dx.doi.org/10.1519/jsc.0b013e31816611ea.

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18

González-Badillo, Juan José, Pedro Jiménez-Reyes, and Jorge Ramírez-Lechuga. "Determinant Factors of the Squat Jump in Sprinting and Jumping Athletes." Journal of Human Kinetics 58, no. 1 (August 1, 2017): 15–22. http://dx.doi.org/10.1515/hukin-2017-0067.

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AbstractThe aim of this study was to assess the relationship between strength variables and maximum velocity (Vmax) in the squat jump (SJ) in sprinting and jumping athletes. Thirty-two sprinting and jumping athletes of national level (25.4 ± 4.5 years; 79.4 ± 6.9 kg and 180.4 ± 6.0 cm) participated in the study. Vmax in the SJ showed significant relationships with peak force 1 (PF1) (r = 0.82, p ≤ 0.001), peak force 2 (PF2) (r = 0.68, p ≤ 0.001), PF2 by controlling for PF1 (r = 0.30, non-significant), the maximum rate of force development at peak force 1 (RFDmax1) (r = 0.62, p ≤ 0.001), mean RFD 1 (RFDmean1) (r = 0.48, p ≤ 0.01), mean RFD 2 (RFDmean2) (r = 0.70, p ≤ 0.001), force at RFDmax1 (r = 0.36, p ≤ 0.05), force at RFDmax2 (r = 0.83, p ≤ 0.001) and force at RFDmax2 by controlling for PF1 (r = 0.40, p ≤ 0.05). However, Vmax in the SJ was associated negatively with the ratio PF2/PF1 (r = -0.54, p ≤ 0.01), time at peak force 2 (Tp2) (r = -0.64, p ≤ 0.001) and maximum rate of force development at peak force 2 (RFDmax2) (r = -0.71, p ≤ 0.001). These findings indicate that the peak force achieved at the beginning of the movement (PF1) is the main predictor of performance in jumping, although the RFDmax values and the ratio PF2/PF1 are also variables to be taken into account when analyzing the determinant factors of vertical jumping.
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19

Sosa, Carlos, Alberto Lorenzo, Juan Trapero, Carlos Ribas, Enrique Alonso, and Sergio L. Jimenez. "Specific Absolute Velocity Thresholds during Male Basketball Games Using Local Positional System; Differences between Age Categories." Applied Sciences 11, no. 10 (May 12, 2021): 4390. http://dx.doi.org/10.3390/app11104390.

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Анотація:
The aim of this study was (I) to establish absolute specific velocity thresholds during basketball games using local positional system (LPS) and (II) to compare the speed profiles between various levels of competitions. The variables recorded were total distance (TD); meters per minute (m·min); real time (min); maximum speed (Km h−1), distance (m), percentage distance, and percentage duration invested in four speed zones (standing–walking; jogging; running; and high-speed running). Mean and standard deviation (±SD) were calculated, and a separate one-way analysis of variance was undertaken to identify differences between competitions. TD (3188.84 ± 808.37 m) is covered by standing–walking (43.51%), jogging (36.58%), running (14.68%), and sprinting (5.23%) activities. Overall, 75.22% of the time is invested standing–walking, jogging (18.43%), running (4.77%), and sprinting (1.89%). M·min (large effect size), % duration zone 2 (moderate effect size); distance zone 4 (large effect size), and % distance zone 4 (very large effect size) are significantly higher during junior than senior. However, % distance zone 1 (large effect size) and % duration zone 1 (large effect size) were largely higher during senior competition. The findings of this study reveal that most of the distance and play time is spent during walking and standing activities. In addition, the proportion of time spent at elevated intensities is higher during junior than in senior competition.
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20

Baena-Raya, Andrés, Dolores García-Ortega, Sergio Sánchez-López, Alberto Soriano-Maldonado, Pedro Jiménez Reyes, and Manuel A. Rodríguez-Pérez. "The Influence of Sprint Mechanical Properties on Change of Direction in Female Futsal Players." Journal of Human Kinetics 79, no. 1 (July 10, 2021): 221–28. http://dx.doi.org/10.2478/hukin-2021-0075.

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Abstract The aim of the present study was to analyze the association of the sprint force-velocity profile [Hzt FV profile] variables with change of direction [COD] performance in female futsal players. Twelve female futsal players (age: 19.83 ± 4.2 years; body height: 160.75 ± 8.37 cm; body mass: 57.64 ± 8.3 kg) volunteered to be evaluated in the following assessments: Hzt FV profile, 505 test, modified 505 test [M505test] and V-cut test. The Spearman’s correlation coefficient [rs] (p < 0.05) was used to determine the relationship of the mechanical variables of the sprint (maximum power output [Pmax], maximum horizontal force production [F0] and maximum velocity [V0]) with COD performance. V0 showed a very large significant association with the 505 test (rs = -0.767; 90% CI: (-0.92 to -0.43); p < 0.01) and a large association with the V-cut test (rs = -0.641; 90% CI: (-0.86 to -0.21); p < 0.05), whereas Pmax was strongly associated with results of the 505 test (rs = -0.821; 90% CI: (-0.94 to -0.55); p < 0.01) and largely associated with the V-cut test results (rs = -0.596; 90% CI: (-0.84 to -0.14); p < 0.05). In conclusion, maximal power and velocity output during sprinting are determinant factors to successful COD in 180º and 45º cuts, thus, the Hzt FV profile should be assessed in female futsal players to better understand the influence of sprint mechanical properties on COD performance and prescribe individualized training programs
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21

Rousopoulos, Evangelos, Carlton Cooke, Giorgos Paradisis, Elias Zacharogiannis, Eleni Patrikia Kouyoufa, and Kevin Till. "The Physiological Profile of Male Professional Soccer Players: The Effect of Playing Division." Journal of Biomedical Research & Environmental Sciences 2, no. 11 (December 2021): 1078–84. http://dx.doi.org/10.37871/jbres1351.

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The purpose of this study was to present the physiological profile of male soccer players who compete in the professional (Division [D] 1, 2, 3) and semi-professional (D4) Greek soccer leagues, and to compare their physiological profile according to playing division. Using 1,095 players (age: 25.2 ± 4.7 years), twelve anthropometric and physiological characteristics (age, height, body mass, BMI, VO2max, velocity of VO2max velocity at ventilatory threshold, maximum heart rate, maximum lactate, squat jump, 35 m sprint and sprinting fatigue index) were assessed. Factorial analysis of variance revealed a significantly (p < 0.05) enhanced physiological profile amongst the professional, compared to semi-professional players, for 10 of the 12 characteristics assessed between divisions. Regarding aerobic parameters, velocity at maximum oxygen uptake was the variable which discriminated professional, from semi-professional players most. With reference to anaerobic parameters, the 35m sprint was the variable which differentiated players between divisions (i.e. D1/D2 vs. D3/D4). Overall, findings in this study present the physiological profile of soccer players within the specified Greek soccer divisions, with differences identified between professional, and semi-professional divisions. These findings suggest that advanced physiological profiles may contribute to a player’s progression to higher divisions of Greek professional soccer.
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22

Marques, Mário, Helena Gil, Rui Ramos, Aldo Costa, and Daniel Marinho. "Relationships Between Vertical Jump Strength Metrics and 5 Meters Sprint Time." Journal of Human Kinetics 29, no. 1 (September 1, 2011): 115–22. http://dx.doi.org/10.2478/v10078-011-0045-6.

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Relationships Between Vertical Jump Strength Metrics and 5 Meters Sprint TimeThe aim of this study was to examine the relationship between short sprint time (5 m) and strength metrics of the countermovement jump (CMJ) using a linear transducer in a group of trained athletes. Twenty-five male, trained subjects volunteered to participate in the study. Each volunteer performed 3 maximal CMJ trials on a Smith machine. Peak instantaneous power was calculated by the product of velocity taken with the linear transducer. For sprint testing, each subject performed three maximum 5 m sprints. Only the best attempt was considered in both tests. Pearson product-moment correlation coefficients between 5 m sprint performance and strength metrics of the CMJ were generally positive and of clear moderate to strong magnitude (r = -0.664 to -0.801). More noticeable was the significant predictive value of bar displacement time (r= ~0.70) to sprint performance. Nevertheless, a non-significant predictive value of peak bar velocity and rate of force development measurements was found. These results underline the important relationship between 5 m sprint and maximal lower body strength, as assessed by the force, power and bar velocity displacement. It is suggested that sprinting time performance would benefit from training regimens aimed to improve these performance qualities.
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Douglas, Jamie, Simon Pearson, Angus Ross, and Mike McGuigan. "Reactive and eccentric strength contribute to stiffness regulation during maximum velocity sprinting in team sport athletes and highly trained sprinters." Journal of Sports Sciences 38, no. 1 (October 19, 2019): 29–37. http://dx.doi.org/10.1080/02640414.2019.1678363.

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24

Pearce, Leesa, Carl Woods, Wade Sinclair, and Anthony Leicht. "Officiating Role Influences the Physical Match Activity Profiles of Rugby League Touch Judges and Referees." Journal of Human Kinetics 58, no. 1 (August 1, 2017): 225–31. http://dx.doi.org/10.1515/hukin-2017-0087.

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Анотація:
Abstract This study investigated the effect of the officiating role on physical activity profiles of rugby league match officials during match-play. Physical performance indicators were collated from 23 match officials, resulting in 78 observations. Match officials were categorised into two groups: referees and touch judges. Microtechnology facilitated the quantification of total distance (m), relative distance (m⋅min-1), maximum velocity (m⋅s-1), the percentage of high intensity running distance (% total > 3.01 m⋅s-1), walking distance (<1 m⋅s-1), jogging distance (1.01 – 3 m⋅s-1), fast jogging distance (3.01 - 5 m⋅s-1), and sprinting distance (>5 m⋅s-1). Multivariate analysis modelled the main effect of the officiating role with follow up univariate analyses identifying significant differences. A significant effect was noted (V = 750; F(8, 66) = 24.71; p < 0.05) with referees covering a greater total distance (7767 ± 585 vs. 7022 ± 759 m), relative distance (90 ± 6 vs. 82 ± 8 m⋅min-1), jogging distance (3772 ± 752 vs. 3110 ± 553 m), and fast jogging distance (2565 ± 631 vs. 1816 ± 440 m) compared to touch judges. Touch judges covered greater distances while sprinting (1012 ± 385 vs. 654 ± 241 m). Results provide important guidance in the development of training programs for match officials.
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Suydam, Stephen M., Kurt Manal, and Thomas S. Buchanan. "The Advantages of Normalizing Electromyography to Ballistic Rather than Isometric or Isokinetic Tasks." Journal of Applied Biomechanics 33, no. 3 (June 2017): 189–96. http://dx.doi.org/10.1123/jab.2016-0146.

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Анотація:
Isometric tasks have been a standard for electromyography (EMG) normalization stemming from anatomic and physiologic stability observed during contraction. Ballistic dynamic tasks have the benefit of eliciting maximum EMG signals for normalization, despite having the potential for greater signal variability. It is the purpose of this study to compare maximum voluntary isometric contraction (MVIC) to nonisometric tasks with increasing degrees of extrinsic variability, ie, joint range of motion, velocity, rate of contraction, etc., to determine if the ballistic tasks, which elicit larger peak EMG signals, are more reliable than the constrained MVIC. Fifteen subjects performed MVIC, isokinetic, maximum countermovement jump, and sprint tasks while EMG was collected from 9 muscles in the quadriceps, hamstrings, and lower leg. The results revealed the unconstrained ballistic tasks were more reliable compared to the constrained MVIC and isokinetic tasks for all triceps surae muscles. The EMG from sprinting was more reliable than the constrained cases for both the hamstrings and vasti. The most reliable EMG signals occurred when the body was permitted its natural, unconstrained motion. These results suggest that EMG is best normalized using ballistic tasks to provide the greatest within-subject reliability, which beneficially yield maximum EMG values.
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Tottori, Nobuaki, and Satoshi Fujita. "Effects of Plyometric Training on Sprint Running Performance in Boys Aged 9–12 Years." Sports 7, no. 10 (October 10, 2019): 219. http://dx.doi.org/10.3390/sports7100219.

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Анотація:
Skilled sprinting is fundamental in many sports, especially to improve athletic performance in youth. This study therefore aimed to investigate the effect of plyometric training on sprint performance in boys aged 9–12 years. Twenty boys were divided into a plyometric training group (n = 9) and a control training group (n = 11). In both groups, participants performed respective training programs once per week for 8 weeks with measurements at baseline and post-intervention. Sprint performance was assessed by 50-m sprint time, sprint velocity, step frequency and step length at 10-m intervals. Jumping performance was assessed using horizontal, vertical and rebound jumps. The plyometric training group showed an improved sprint velocity at 20–30 m, 30–40 m and 40–50 m, and step length at 0–10 m, 20–30 m and 30–40 m (p < 0.05). Furthermore, only the plyometric group showed an increased standing long jump distance and rebound jump performance (p < 0.05). The control group did not show any significant changes in any variable. Our findings suggest that plyometric training in pre-adolescent boys improves sprint velocity and step length at the maximum velocity phase concomitant with increased horizontal and rebound jump performance.
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Zabaloy, Santiago, Jorge Carlos-Vivas, Tomás T. Freitas, Fernando Pareja-Blanco, Lucas Pereira, Irineu Loturco, Thomas Comyns, Javier Gálvez-González, and Pedro E. Alcaraz. "Relationships between Resisted Sprint Performance and Different Strength and Power Measures in Rugby Players." Sports 8, no. 3 (March 14, 2020): 34. http://dx.doi.org/10.3390/sports8030034.

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Анотація:
This study aimed to investigate the relationship between a specific isometric-strength sprint test (SIST) and unresisted maximum velocity (Vmax), sprint times across different loading conditions, and the velocity loss (Vloss) loads required to achieve each intended Vloss condition during resisted sprint training (RST) in rugby players. Additionally, the investigation examined the relationship between strength in the back-squat one-repetition maximum (1RM-SQ) as well as isometric squat (ISQT), jumps, and sprint performance variables. Twenty (n = 20) male amateur rugby players performed, on two separate occasions, a structural multiple-joint assessment of jumps, strength, and sprint performance. Interestingly, SIST revealed moderate correlations (r = 0.453 to 0.681; p < 0.05) between 1RM-SQ and ISQT. The SISTrel (relative to body mass), but not SIST, used in the present study showed moderate correlations (r = 0.508 to 0.675; p < 0.05) with the loads needed to reach 10%, 30%, and 50% of Vloss during RST. The SISTrel that measures resultant force application in a more sprint-related position explains much of the individual response of each athlete during sprinting towing a sled and can also be used to prescribe and quantify loads in the RST in a more objective and individual manner.
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Nobari, Hadi, Özgür Eken, Pablo Prieto-González, João Paulo Brito, and Rafael Oliveira. "Associations among Maturity, Accumulated Workload, Physiological, and Body Composition Factors in Youth Soccer Players: A Comparison between Playing Positions." Biology 11, no. 11 (November 2, 2022): 1605. http://dx.doi.org/10.3390/biology11111605.

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Анотація:
The purposes of this study were: (i) to analyze the correlation between accumulated workload (AW)—based on season periods—with maturity, linear sprints, maximum oxygen uptake (VO2max), maximum heart rate, and body composition; and (ii) to compare the playing positions based on the mentioned parameters. Twenty-one elite soccer players under the age of 14 participated in the study. They were divided into five groups based on playing positions. The in-season weekly AW was recorded for 26 weeks into two separated periods of 13 weeks (AW-1 and AW-2). Similarly, the following parameters were assessed: body mass, standing and sitting height, body mass index, body fat percentage, maturity offset, age at peak height velocity (PHV), sprinting ability (10 m and 30 m), and VO2max. The main significant differences between playing positions were found for weight, height, sitting height, and sprinting at 10 m and 30 m. No correlation was observed between AW (based on periods) and maturity or between VO2max and AW-2. AW-1 denoted a large positive correlation with AW-2. AW-1 had a moderate negative correlation with VO2max, whereas PHV and maturity presented a strong negative correlation. Young soccer players’ maturity statuses and fitness levels do not imply differences between AW-1 and AW-2. However, the higher the AW in the first half of the season, the higher the AW in the second half. The absence of significant differences between player positions could be associated with the similar training regardless of the playing position. Moreover, soccer positively influences performance in short sprints (10 m), midfielders being the fastest.
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29

Barrett, Steve. "Monitoring Elite Soccer Players’ External Loads Using Real-Time Data." International Journal of Sports Physiology and Performance 12, no. 10 (November 1, 2017): 1285–87. http://dx.doi.org/10.1123/ijspp.2016-0516.

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Purpose: To assess the validity of measuring locomotor activities and PlayerLoad using real-time (RT) data collection during soccer training. Methods: Twenty-nine English soccer players participated. Each player wore the same MEMS device (Micromechanical Electrical Systems; S5, Optimeye; CatapultSports, Melbourne, Australia) during 21 training sessions (N = 331 data sets) in the 2015–16 and 2016–17 seasons. An RT receiver (TRX; Catapultsports, Melbourne, Australia) was used to collect the locomotor activities and PlayerLoad data in RT and compared with the postevent downloaded (PED) data. PlayerLoad and locomotor activities (total distance covered; total high-speed running distance covered, >5.5#x00A0;m/s; total sprinting distance covered, >7 m/s; maximum velocity) were analyzed. Results: Correlations were near perfect for all variables analyzed (r = .98–1.00), with a varied level of noise between RT and PED also (0.3–9.7% coefficient of variation). Conclusions: Locomotor activities and PlayerLoad can use both RT and PED concurrently to quantify a player’s physical output during a training session. Caution should be taken with higher-velocity-based locomotor activities during RT compared to PED.
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30

Caetano, Fabio Giuliano, Murilo José de Oliveira, Ana Lorena Marche, Fábio Yuzo Nakamura, Sergio Augusto Cunha, and Felipe Arruda Moura. "Characterization of the Sprint and Repeated-Sprint Sequences Performed by Professional Futsal Players, According to Playing Position, During Official Matches." Journal of Applied Biomechanics 31, no. 6 (December 2015): 423–29. http://dx.doi.org/10.1123/jab.2014-0159.

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Анотація:
The purposes of this study were to investigate sprints and to characterize repeated-sprint sequences (RS) performed by athletes during professional futsal matches. We analyzed 97 players during 5 official matches using the DVideo automatic tracking system. The sprints were analyzed during the first and second halves according to playing position, and RS were categorized according to the number of sprints and the time between them. The results showed an increase (F[1, 2520] = 3.96; P = .046) in the sprint duration from the first (mean = 3.1 ± 1.3) to the second half (mean = 3.2 ± 1.2). However, no differences were found for other variables (distance covered, peak velocity, initial velocity, recovery time between sprints, and sprints performed per minute) or among playing positions. In addition, when considering RS, the results showed that RS comprising two sprints interspersed with a maximum of 15 seconds of recovery were significantly more frequent than other RS. The findings of this study characterizing the sprinting features of futsal players can help coaches to plan physical training and assessments according to the requirements of the sport.
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Hermosilla-Palma, Felipe, Juan Francisco Loro-Ferrer, Pablo Merino-Muñoz, Nicolás Gómez-Álvarez, Alejandro Bustamante-Garrido, Hugo Cerda-Kohler, Moacyr Portes-Junior, and Esteban Aedo-Muñoz. "Changes in the Mechanical Properties of the Horizontal Force-Velocity Profile during a Repeated Sprint Test in Professional Soccer Players." International Journal of Environmental Research and Public Health 20, no. 1 (December 30, 2022): 704. http://dx.doi.org/10.3390/ijerph20010704.

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The objective was to analyze the changes in the horizontal force-velocity profile (HFVP) during the execution of repeated sprinting. Methods: Seventeen first-division Chilean soccer players completed a repeated sprint protocol consisting of eight sprints of 30 m with 25-s pauses between repetitions. The behavior of HFVP variables in each attempt was recorded from video recordings and analysis in the MySprint® application. Results: Differences (p < 0.05) were found between sprints in the following: time (T), starting from sprint 5 (F = 35.6; η2p = 0.69); theoretical maximum speed (V0), starting from sprint 4 (F = 29.3; η2p = 0.51); maximum power (PM), starting from sprint 5 (F = 17; η2p = 0.52); rate of decrease in force index produced at each step (DRF), starting from sprint 1 (F = 3.20; η2p = 0.17); and RF10, starting from sprint 1 (F = 15.5; η2p = 0.49). In comparison, F0 and RFpeak did not present any differences (p > 0.05). Conclusion: The HFVP variables more sensitive to the effects of fatigue induced by an RSA protocol are those associated with the production of force at high speeds, being V0, DRF, and Pmax, while those that contribute to the generation of force at the beginning of the sprint, F0 and RFpeak, do not present essential variations.
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32

Young, Warren, Stuart Cormack, and Michael Crichton. "Which Jump Variables Should Be Used to Assess Explosive Leg Muscle Function?" International Journal of Sports Physiology and Performance 6, no. 1 (March 2011): 51–57. http://dx.doi.org/10.1123/ijspp.6.1.51.

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Purpose:The main purpose of this study was to determine the relationships between countermovement jump (CMJ) variables and acceleration and maximum speed performance.Methods:Twenty-three elite Australian football players were tested on a CMJ, which yielded several kinematic and kinetic variables describing leg muscle function. A 40 m sprint was also conducted to assess acceleration (10 m time) and an estimate of maximum speed (fying 20 m time). Players from one Australian Football League (AFL) club were tested and Pearson correlations for CMJ variables and sprint performance were calculated.Results:Jump height, peak velocity, peak force, and peak power had less than 50% common variance, and therefore represented independent expressions of CMJ performance. Generally, the correlations between CMJ variables and sprinting performance were stronger for maximum speed (small to large effect sizes) than for acceleration (trivial to moderate sizes). The variable that produced the strongest correlation with acceleration was jump height (r = -0.430, P = .041) and with maximum speed was peak power/weight (r = -0.649, P = .001).Conclusions:The results indicate that if an integrated system comprising a position transducer and a force platform is available for CMJ assessment, jump height and peak power/weight are useful variables to describe leg muscle explosive function for athletes who perform sprints.
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Shahab, Samad, Ida B. Steendahl, Ludwig Ruf, Tim Meyer, and Bas Van Hooren. "Sprint performance and force-velocity profiling does not differ between artificial turf and concrete." International Journal of Sports Science & Coaching 16, no. 4 (February 25, 2021): 968–75. http://dx.doi.org/10.1177/1747954121996966.

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Purpose Force-velocity-power (F-v-P) profiling can illustrate an individual’s sprinting capabilities, but no study has explored the effect of different running surfaces on F-v-P outcomes. Method Twelve elite youth football players (age 16.3 ± 0.5 years, mass 67.3 ± 5.4 kg, height 176.2 ± 4.6 cm) performed two 30 m sprints on concrete and artificial turf in a randomised order on two testing days. Differences between surfaces were determined using repeated-measures ANOVA (P < 0.05), whilst the coefficient of variation (CV), smallest worthwhile change and standard error of measurement were calculated to quantify reliability. Results No significant differences were found between surfaces over the average of two days. High reliability was evident for 30 m sprint time, theoretical maximum horizontal velocity and ratio of force on both surfaces (CV≤∼5%), while the remaining outputs were not reliable (CV >10%). Conclusion These findings show that F-v-P profiling does not differ between concrete and artificial turf. However, higher variability on the more unfamiliar concrete surface suggests that the testing surface should match the playing surface. Since the standard error of measurement is larger than the smallest worthwhile change, the ability of this method to monitor seasonal changes may be limited in youth elite soccer players.
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34

Loturco, I., R. Kobal, T. Maldonado, A. Piazzi, A. Bottino, K. Kitamura, C. Abad, L. Pereira, and F. Nakamura. "Jump Squat is More Related to Sprinting and Jumping Abilities than Olympic Push Press." International Journal of Sports Medicine 38, no. 08 (December 14, 2015): 604–12. http://dx.doi.org/10.1055/s-0035-1565201.

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Анотація:
AbstractThe aim of this study was to test the relationships between jump squat (JS) and Olympic push press (OPP) power outputs and performance in sprint, squat jump (SJ), countermovement jump (CMJ) and change of direction (COD) speed tests in elite soccer players. 27 athletes performed a maximum power load test to determine their bar mean propulsive power (MPP) and bar mean propulsive velocity (MPV) in the JS and OPP exercises. Magnitude-based inference was used to compare the exercises. The MPV was almost certainly higher in the OPP than in the JS. The MPP relative to body mass (MPP REL) was possibly higher in the OPP. Only the JS MPP REL presented very large correlations with linear speed (r>0.7, for speed in 5, 10, 20 and 30 m) and vertical jumping abilities (r>0.8, for SJ and CMJ), and moderate correlation with COD speed (r=0.45). Although significant (except for COD), the associations between OPP outcomes and field-based measurements (speed, SJ and CMJ) were all moderate, ranging from 0.40 to 0.48. In a group composed of elite soccer players, the JS exercise is more associated with jumping and sprinting abilities than the OPP. Longitudinal studies are needed to confirm if these strong relationships imply superior training effects in favor of the JS exercise.
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35

Li, Kai, Jinqian Zhang, Qingling Qu, Bairan Li, and Sukwon Kim. "Application of Biomechanics Based on Intelligent Technology and Big Data in Physical Fitness Training of Athletes." Contrast Media & Molecular Imaging 2022 (August 26, 2022): 1–12. http://dx.doi.org/10.1155/2022/7323146.

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Анотація:
Physical training has a high degree of participation all over the world. With the opening of the era of national fitness, physical training has become more popular from the original specialization, and the complex training methods and contents have gradually become simplified. The development and change of physical training has also brought many problems to the professional training of athletes, such as high training intensity but poor effect, insufficient training posture, and long-term physical injury. In order to help athletes achieve better results in physical training and reduce the probability of injury, taking sprint training as an example, this article adopted the sports and body data of elite athletes through intelligent technology and big data analysis, established a human motion model from the perspective of biomechanics, and then conducted a corresponding test run experiment for athletes. The experimental results suggested that drag resistance running could improve the specific strength quality of sprinting. At the same time, when using resistance load for training, the maximum speed should not exceed 90% of the maximum speed without resistance. The average horizontal maximum velocity decreased by approximately 9% when training under a resistance load, and the best training results were obtained by training athletes within this range.
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36

Mara, Jocelyn K., Kevin G. Thompson, and Kate L. Pumpa. "Physical and Physiological Characteristics of Various-Sided Games in Elite Women’s Soccer." International Journal of Sports Physiology and Performance 11, no. 7 (October 2016): 953–58. http://dx.doi.org/10.1123/ijspp.2015-0087.

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Анотація:
Purpose:To investigate the physical and physiological response to different formats of various-sided games.Methods:Eighteen elite women’s soccer players wore 15-Hz global positioning system devices and heart-rate (HR) monitors during various-sided games (small, 4 vs 4 and 5 vs 5; medium, 6 vs 6 and 7 vs 7; large, 8 vs 8 and 9 vs 9).Results:Players covered more relative sprinting distance during large-sided games than in small-sided (P < .001, d = 0.69) and medium-sided (P < .001, d = 0.54) games. In addition, a greater proportion of total acceleration efforts that had a commencement velocity <1 m/s were observed in small-sided games (44.7% ± 5.5%) than in large-sided games (36.7% ± 10.6%) (P = .018, d = 0.94). This was accompanied by a greater proportion of acceleration efforts with a final velocity equivalent to the sprint threshold in large-sided games (15.4% ± 7.7%) than in small-sided games (5.2% ± 2.5%) (P < .001, d = 1.78). The proportion of time spent in HR zone 4 (>85% maximum HR) was greater during small-sided games (69.8% ± 2.5%) than in medium- (62.1% ± 2.8%, d = 2.90) and large-sided games (54.9% ± 3.1%) (P < .001, d = 5.29).Conclusions:The results from this study demonstrate that coaches can use small-sided games as an aerobic conditioning stimulus and to develop players’ explosiveness and repeat-sprint ability over short durations. Large-sided games can be used to maintain aerobic capacity and develop maximum speed over longer distances.
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37

Ramey, Melvin R., and Keith R. Williams. "Ground Reaction Forces in the Triple Jump." International Journal of Sport Biomechanics 1, no. 3 (August 1985): 233–39. http://dx.doi.org/10.1123/ijsb.1.3.233.

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Анотація:
Ground reaction forces were obtained for the three phases of the triple jump for four collegiate triple jumpers, two men and two women. A single force platform was used, which thereby required the subjects to execute three separate jumps to produce a single triple jump record. The vertical force records for each phase showed two peaks having magnitudes in the range of 7 to 12 times body weight (BW) and 3.3 to 5 BW, respectively. These magnitudes are substantially higher than has been reported by others for distance running, sprinting, and in some cases other jumps. The maximum horizontal forces act to decrease the velocity of the mass center, but to different degrees for the different subjects. The data show that for any phase of the jump there is considerable variability in the timing and magnitudes of the force records among the different subjects although general patterns are similar. The results suggest that the use of mean force data from a number of subjects may conceal important differences between the way individuals execute the jump.
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38

Sadeghi, Faraz, Ahmad Kueh, Ali Bagheri Fard, and Nasim Aghili. "Vibration Characteristics of Composite Footbridges under Various Human Running Loads." ISRN Civil Engineering 2013 (October 22, 2013): 1–8. http://dx.doi.org/10.1155/2013/817384.

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Анотація:
Various types of human running dynamic loads are numerically studied and compared to assess vibration characteristics of the light and slender composite footbridges. Running, which is a common human activity, has been categorized with respect to its intensity into jogging, normal running, and sprinting. To explore the footbridge’s performance, the vibration responses are investigated through a series of analyses in terms of the peak accelerations and displacements. In the model verification, the acquired first natural frequency of structure has shown good agreement with the value reported in the literature. The structural performance of the slender composite footbridge is then evaluated with regard to the serviceability requirement given by the current design standards. It is generally found that the maximum acceleration of the composite footbridge due to the excitation of one person running varies under different running types because of diversities in the velocity and the step frequency. Furthermore, it is shown that the investigated structure provides sufficient human comfort against vibrations for all the examined three types of running loads.
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Haugen, Thomas, Espen Tønnessen, and Stephen Seiler. "9.58 and 10.49: Nearing the Citius End for 100 m?" International Journal of Sports Physiology and Performance 10, no. 2 (March 2015): 269–72. http://dx.doi.org/10.1123/ijspp.2014-0350.

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Анотація:
Human upper performance limits in the 100-m sprint remain the subject of much debate. The aim of this commentary is to highlight the vulnerabilities of prognoses from historical trends by shedding light on the mechanical and physiological limitations associated with human sprint performance. Several conditions work against the athlete with increasing sprint velocity; air resistance and braking impulse in each stride increase while ground-contact time typically decreases with increasing running velocity. Moreover, muscle-force production declines with increasing speed of contraction. Individual stature (leg length) strongly limits stride length such that conditioning of senior sprinters with optimized technique mainly must be targeted to enhance stride frequency. More muscle mass means more power and thereby greater ground-reaction forces in sprinting. However, as the athlete gets heavier, the energy cost of accelerating that mass also increases. This probably explains why body-mass index among world-class sprinters shows low variability and averages 23.7 ± 1.5 and 20.4 ± 1.4 for male and female sprinters, respectively. Performance development of world-class athletes indicates that ~8% improvement from the age of 18 represents the current maximum trainability of sprint performance. However, drug abuse is a huge confounding factor associated with such analyses, and available evidence suggests that we are already very close to “the citius end” of 100-m sprint performance.
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40

Forcher, Leon, Leander Forcher, Darko Jekauc, Alexander Woll, Timo Gross, and Stefan Altmann. "Center backs work hardest when playing in a back three: The influence of tactical formation on physical and technical match performance in professional soccer." PLOS ONE 17, no. 3 (March 17, 2022): e0265501. http://dx.doi.org/10.1371/journal.pone.0265501.

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Анотація:
The purpose of this study was to investigate whether tactical formation affects the physical and technical match performance of professional soccer players in the first German Bundesliga. From official match data of the Bundesliga season 2018/19, physical (total distance, high-intensity distance, sprinting distance, accelerations, maximum velocity) and technical performance (short/middle/long passes, dribblings, ball-possessions) of players were analyzed. Players were categorized into five playing positions (center back, full back, central midfielder, wide midfielder, forward) and teams into eight different tactical formations (4-4-2, 4-4-2 diamond, 4-2-2-2, 4-3-3, 4-5-1, 4-2-3-1, 3-4-3, 3-5-2). Results revealed that the degree to which tactical formation affects match performance is position dependent. In terms of physical performance, center backs and full backs showed highest sprinting distances when playing in a formation with only three defenders in the back row (3-4-3, 3-5-2) compared to all other formations (ES range: 0.13≤ES≤1.27). Regarding technical performance, all positions except forwards displayed fewer short passes, middle passes and ball-possessions in the formations 4-3-3 and 4-2-3-1 compared to all other formations (0.02≤ES≤1.19). In conclusion, physical and technical performance of center backs, full backs and wide midfielders differed markedly between the tactical formations. Conversely, the physical and technical performance of central midfielders and forwards only showed small differences between the different tactical formations. These findings can help coaches scheduling their practice. For example, if a coach wants to change the playing formation, he can anticipate the physical and technical match performance changes depending on the respective playing position.
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41

Freitas, Tomás T., Lucas A. Pereira, Pedro E. Alcaraz, Ademir F. S. Arruda, Aristide Guerriero, Paulo H. S. M. Azevedo, and Irineu Loturco. "Influence of Strength and Power Capacity on Change of Direction Speed and Deficit in Elite Team-Sport Athletes." Journal of Human Kinetics 68, no. 1 (August 21, 2019): 167–76. http://dx.doi.org/10.2478/hukin-2019-0069.

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Анотація:
AbstractThe aim of the present study was to investigate the influence of maximum strength and power levels on change of direction (COD) ability and deficit in elite soccer and rugby players. Seventy-eight elite athletes (soccer, n = 46; rugby, n = 32) performed the following assessments: squat and countermovement jumps (SJ and CMJ), 1 repetition-maximum in the half-squat exercise (HS 1RM), peak power (PP) in the jump-squat exercise, and 20-m linear sprint and Zigzag COD tests. Utilizing the median split analysis, athletes were divided into two groups according to their HS 1RM and PP JS (e.g., higher and lower HS 1RM and higher and lower PP JS). The magnitude-based inference method was used to analyze the differences between groups in the physical performance tests. Athletes in the high strength and power groups outperformed their weaker and less powerful counterparts in all speed and power measurements (i.e., 5-, 10-, and 20-m sprint velocity, Zigzag COD speed, and CMJ and SJ height). In contrast, stronger and more powerful athletes displayed greater COD deficits. The present data indicate that players with superior strength-power capacity tend to be less efficient at changing direction, relative to maximum sprinting speed, despite being faster in linear trajectories. From these results, it appears that current strength and power training practices in team-sports are potentially not the “most appropriate” to increase the aptitude of a given athlete to efficiently utilize his/her neuromuscular abilities during COD maneuvers. Nevertheless, it remains unknown whether more multifaceted training programs are effective in decreasing COD deficits.
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42

Acker, Katrin S., Tim V. M. Eberle, Dustin J. Oranchuk, Shelley N. Diewald, Aaron M. Uthoff, Chris Korfist, and John B. Cronin. "Kinetic and Kinematic Effects of Asymmetrical Loading of the Lower Limb During High-Speed Running." Journal of Sport Rehabilitation 31, no. 3 (March 1, 2022): 313–18. http://dx.doi.org/10.1123/jsr.2021-0131.

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Анотація:
Context: Light lower-limb wearable resistance has little effect on running biomechanics. However, asymmetrical wearable resistance may potentially alter the kinetics and kinematics of high speed, enabling greater loading or unloading of an injured or rehabilitative lower limb. Design: A cross-sectional study design was used to quantify the influence of asymmetric calf loading on the kinematics and kinetics during 90% maximum sprinting velocity. Methods: Following a familiarization session, 12 (male = 7 and female = 5) physically active volunteers ran at 90% of maximal velocity. In random order, participants ran with zero (0) wearable resistance and with loads of 300 g (L300) and 600 g (L600) fixed to one shank. A nonmotorized treadmill quantified vertical and horizontal kinetics and step kinematics. The kinetics and kinematics of the loaded (L0, L300, and L600) and unloaded (UL; UL0, UL300, and UL600) limbs were compared. Results: Vertical step ground reaction force of the loaded limb tended to increase between unloaded and 300 and 600 conditions (effect size [ES] = 0.48 to 0.76, all P ≤ .12), while the horizontal step force of the UL tended to decrease (ES = 0.54 to 1.32, all P ≤ .09) with greater external loading. Step length increased in the UL in 0 versus 300 and 600 conditions (ES = 0.60 to 0.70, all P ≤ .06). Step frequency decreased in the ULs in unloaded versus 300 and 600 conditions (ES = 0.73 to 1.10, all P ≤ .03). Mean step velocity tended to be greater in the ULs than the 300 and 600 conditions (ES = 0.52 to 1.01, all P ≤ .10). Only 4 of 16 variables were significantly different between the 300 and 600 conditions. Conclusions: Asymmetrical shank resistance could be used during high-speed running to reduce or increase the kinetic loading of an injured/rehabilitative limb during return to play protocols. Asymmetrical wearable resistance could also be used to alter step kinematics in runners with known asymmetries. Finally, meaningful alterations in high-speed running biomechanics can be achieved with only 300 g of shank loading.
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43

Nelson, Frank E., and Bruce C. Jayne. "The effects of speed on thein vivoactivity and length of a limb muscle during the locomotion of the iguanian lizardDipsosaurus dorsalis." Journal of Experimental Biology 204, no. 20 (October 15, 2001): 3507–22. http://dx.doi.org/10.1242/jeb.204.20.3507.

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SUMMARYThe caudofemoralis muscle is the largest muscle that inserts onto the hindlimb of most ectothermic tetrapods, and previous studies hypothesize that it causes several movements that characterize the locomotion of vertebrates with a sprawling limb posture. Predicting caudofemoralis function is complicated because the muscle spans multiple joints with movements that vary with speed. Furthermore, depending on when any muscle is active relative to its change in length, its function can change from actively generating mechanical work to absorbing externally applied forces. We used synchronized electromyography, sonomicrometry and three-dimensional kinematics to determine in vivo caudofemoralis function in the desert iguana Dipsosaurus dorsalis for a wide range of speeds of locomotion from a walk to nearly maximal sprinting (50–350 cm s–1). Strain of the caudofemoralis increased with increasing tail elevation and long-axis rotation and protraction of the femur. However, knee extension only increased caudofemoralis strain when the femur was protracted. The maximum and minimum length of the caudofemoralis muscle and its average shortening velocity increased from the slowest speed up to the walk–run transition, but changed little with further increases in speed. The times of muscle shortening and lengthening were often not equal at higher locomotor speeds. Some (20–25 ms) activity occurred during lengthening of the caudofemoralis muscle before footfall. However, most caudofemoralis activity was consistent with performing positive mechanical work to flex the knee shortly after foot contact and to retract and rotate the femur throughout the propulsive phase.
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44

Irschick, D. J., and B. C. Jayne. "Effects of incline on speed, acceleration, body posture and hindlimb kinematics in two species of lizard Callisaurus draconoides and Uma scoparia." Journal of Experimental Biology 201, no. 2 (January 15, 1998): 273–87. http://dx.doi.org/10.1242/jeb.201.2.273.

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Анотація:
We examined the effects of incline on locomotor performance and kinematics in two closely related species of iguanian lizards that co-occur in sandy desert habitats. Callisaurus draconoides differs from Uma scoparia of equal snout-vent length by being less massive and having greater limb and tail lengths. We analyzed high-speed video tapes of lizards sprinting from a standstill on a sand-covered racetrack which was level or inclined 30 degrees uphill. C. draconoides sprinted significantly faster than U. scoparia on both level and uphill sand surfaces, although U. scoparia is considered to be more specialized for sandy habitats. Initial accelerations (over the first 50 ms) did not differ significantly either between species or between inclines within species. Overall, the effects of incline were more pronounced for C. draconoides than for U. scoparia. For example, the incline caused a significant decrease in the maximum stride length of C. draconoides but not in that of U. scoparia. For C. draconoides, uphill stride durations were significantly shorter than on the level surface, and this partially compensated for the effects of shorter uphill stride lengths on velocity. C. draconoides ran bipedally more often than did U. scoparia on both the level and uphill surfaces.
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45

Zhong, Yunjian, Weijie Fu, Shutao Wei, Qing Li, and Yu Liu. "Joint Torque and Mechanical Power of Lower Extremity and Its Relevance to Hamstring Strain during Sprint Running." Journal of Healthcare Engineering 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/8927415.

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Анотація:
The aim of this study was to quantify the contributions of lower extremity joint torques and the mechanical power of lower extremity muscle groups to further elucidate the loadings on hamstring and the mechanics of its injury. Eight national-level male sprinters performed maximum-velocity sprint running on a synthetic track. The 3D kinematic data and ground reaction force (GRF) were collected synchronously. Intersegmental dynamics approach was used to analyze the lower extremity joint torques and power changes in the lower extremity joint muscle groups. During sprinting, the GRF during the stance phase and the motion-dependent torques (MDT) during the swing phase had a major effect on the lower extremity movements and muscle groups. Specifically, during the stance phase, torque produced and work performed by the hip and knee muscles were generally used to counteract the GRF. During the swing phase, the role of the muscle torque changed to mainly counteract the effect of MDT to control the movement direction of the lower extremity. Meanwhile, during the initial stance and late swing phases, the passive torques, namely, the ground reaction torques and MDT produced by the GRF and the inertial movement of the segments of the lower extremity, applied greater stress to the hamstring muscles.
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46

Nickerson, Brett S., Gerald T. Mangine, Tyler D. Williams, and Ismael A. Martinez. "Effect of cluster set warm-up configurations on sprint performance in collegiate male soccer players." Applied Physiology, Nutrition, and Metabolism 43, no. 6 (June 2018): 625–30. http://dx.doi.org/10.1139/apnm-2017-0610.

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Анотація:
The purpose of this study was to determine if back squat cluster sets (CS) with varying inter-repetition rest periods would potentiate greater sprint performance compared with a traditional set parallel back squat in collegiate soccer players. Twelve collegiate male soccer players (age, 21.0 ± 2.0 years; height, 180.0 ± 9.0 cm; body mass, 79.0 ± 9.5 kg) performed a 20-m sprint prior to a potentiation complex and at 1, 4, 7, and 10 min postexercise on 3 separate, randomized occasions. On each occasion, the potentiation complex consisted of 1 set of 3 repetitions at 85% 1-repetition maximum (1RM) for the traditional parallel back squat. However, on 1 occasion the 3-repetition set was performed in a traditional manner (i.e., continuously), whereas on the other 2 occasions, 30s (CS30) and 60 s (CS60) of rest were allotted between each repetition. Repeated-measures ANOVA revealed greater (p = 0.022) mean barbell velocity on CS60 compared with the traditional set. However, faster (p < 0.040) 20-m sprint times were observed for CS30 (3.15 ± 0.16 s) compared with traditional (3.20 ± 0.17 s) only at 10 min postexercise. No other differences were observed. These data suggest that a single cluster set of 3 repetitions with 30-s inter-repetition rest periods at 85% 1RM acutely improves 20-m sprinting performance. Strength and conditioning professionals and their athletes might consider its inclusion during the specific warm-up to acutely improve athletic performance during the onset (≤10 min) of training or competition.
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47

Sauls, Nicole M., and Nicole C. Dabbs. "Differences In Male Collegiate And Recreationally Trained Soccer Players On Balance, Agility, And Vertical Jump Performance." International Journal of Kinesiology and Sports Science 5, no. 4 (October 31, 2017): 45. http://dx.doi.org/10.7575/aiac.ijkss.v.5n.4p.45.

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Анотація:
Objective: The purpose of this investigation was to determine the differences in collegiate and recreationally trained soccer players in sprint, vertical jump, and balance performance. Methods: Twenty-one soccer players, twelve Division II collegiate and nine recreationally trained volunteered to participate. Session one acted as a familiarization day, where the participants were familiarized with testing day protocols. During testing day, participants performed a dynamic warm-up, followed by balance measurements, three countermovement vertical jumps, and pro-agility shuttle test. Results: There were no significant (p>0.05) differences between groups in the all balance variables. Collegiate soccer players had a significantly (p<0.05) greater peak velocity in vertical jump then recreationally trained soccer players. There were significant differences (p<0.05) between groups for maximum for split velocities, where collegiate soccer players were greater than recreationally trained soccer players. There were no significant (p>0.05) differences in groups in all other variables. Conclusion: These results indicate that collegiate, Division II, soccer players had greater vertical jumping and sprinting velocities when compared to recreationally trained soccer players. These results may have been impacted by the lack of resistance training background in either of the two groups. With the addition of more time on a collegiate resistance training program, it is very likely the Division II athletes will see a significant increase in all balance, sprint, and vertical jump performance measures compared to recreationally trained players who receive little to no specialized resistance training.
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48

Alt, Prisca S., Christian Baumgart, Olaf Ueberschär, Jürgen Freiwald, and Matthias W. Hoppe. "Validity of a Local Positioning System during Outdoor and Indoor Conditions for Team Sports." Sensors 20, no. 20 (October 9, 2020): 5733. http://dx.doi.org/10.3390/s20205733.

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Анотація:
This study aimed to compare the validity of a local positioning system (LPS) during outdoor and indoor conditions for team sports. The impact of different filtering techniques was also investigated. Five male team sport athletes (age: 27 ± 2 years; maximum oxygen uptake: 48.4 ± 5.1 mL/min/kg) performed 10 trials on a team sport-specific circuit on an artificial turf and in a sports hall. During the circuit, athletes wore two devices of a recent 20-Hz LPS. From the reported raw and differently filtered velocity data, distances covered during different walking, jogging, and sprinting sections within the circuit were computed for which the circuit was equipped with double-light timing gates as criterion measures. The validity was determined by comparing the known and measured distances via the relative typical error of estimate (TEE). The LPS validity for measuring distances covered was good to moderate during both environments (TEE: 0.9–7.1%), whereby the outdoor validity (TEE: 0.9–6.4%) was superior than indoor validity (TEE: 1.2–7.1%). During both environments, validity outcomes of an unknown manufacturer filter were superior (TEE: 0.9–6.2%) compared to those of a standard Butterworth filter (TEE: 0.9–6.4%) and to unprocessed raw data (TEE: 1.0–7.1%). Our findings show that the evaluated LPS can be considered as a good to moderately valid tracking technology to assess running-based movement patterns in team sports during outdoor and indoor conditions. However, outdoor was superior to indoor validity, and also impacted by the applied filtering technique. Our outcomes should be considered for practical purposes like match and training analyses in team sport environments.
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49

VON SECKENDORFF HOFF, KARIN, and RICHARD JOEL WASSERSUG. "The Kinematics of Swimming in Larvae of the Clawed Frog, Xenopus Laevis." Journal of Experimental Biology 122, no. 1 (May 1, 1986): 1–12. http://dx.doi.org/10.1242/jeb.122.1.1.

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Анотація:
The kinematics of swimming in larval Xenopus laevis has been studied using computer-assisted analysis of high-speed (200 frames s−1) ciné records. The major findings are as follows. 1. At speeds below 6 body lengths (L) per second, tail beat frequency is approximately 10 Hz and, unlike for most aquatic vertebrates, is not correlated with specific swimming speed. At higher speeds, tail beat frequency and speed are positively correlated. 2. Xenopus tadpoles show an increase in the maximum amplitude of the tail beat with increasing velocity up to approximately 6Ls−1. Above that speed amplitude approaches an asymptote at 20 % of body length. 3. Anterior yaw is absent at velocities below 6Ls−1, unlike for other anuran larvae, but is present at higher speeds. 4. At speeds below 6Ls−1 there is a positive linear relationship between length of the propulsive wave (λ) and specific swimming speed. At higher speeds wavelength is constant at approximately 0.8L. 5. There is a shift in the modulation of wavelength and tail beat frequency with swimming speed around 5.6Ls−1, suggesting two different swimming modes. The slower mode is used during open water cruising and suspension feeding. The faster, sprinting mode may be used to avoid predators. 6. Froude efficiencies are similar to those reported for fishes and other anuran larvae. 7. Unlike Rana and Bufo larvae, the axial muscle mass of Xenopus increases dramatically with size from less than 10% of total mass for the smallest animals to more than 45% of total mass for the largest animals. This increase is consistent with maintaining high locomotor performance throughout development.
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50

Nagahara, Ryu, Jean-Benoit Morin, and Masaaki Koido. "Impairment of Sprint Mechanical Properties in an Actual Soccer Match: A Pilot Study." International Journal of Sports Physiology and Performance 11, no. 7 (October 2016): 893–98. http://dx.doi.org/10.1123/ijspp.2015-0567.

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Анотація:
Purpose:To assess soccer-specific impairment of mechanical properties in accelerated sprinting and its relation with activity profiles during an actual match.Methods:Thirteen male field players completed 4 sprint measurements, wherein running speed was obtained using a laser distance-measurement system, before and after the 2 halves of 2 soccer matches. Macroscopic mechanical properties (theoretical maximal horizontal force [F0], maximal horizontal sprinting power [Pmax], and theoretical maximal sprinting velocity [V0]) during the 35-m sprint acceleration were calculated from speed–time data. Players’ activity profiles during the matches were collected using global positioning system units.Results:After the match, although F0 and Pmax did not significantly change, V0 was reduced (P = .038), and the magnitude of this reduction correlated with distance (positive) and number (negative) of high-speed running, number of running (negative), and other low-intensity activity distance (negative) during the match. Moreover, Pmax decreased immediately before the second half (P = .014).Conclusions:The results suggest that soccer-specific fatigue probably impairs players’ maximal velocity capabilities more than their maximal horizontal force-production abilities at initial acceleration. Furthermore, long-distance running, especially at high speed, during the match may induce relatively large impairment of maximal velocity capabilities. In addition, the capability of producing maximal horizontal power during sprinting is presumably impaired during halftime of a soccer match with passive recovery. These findings could be useful for players and coaches aiming to train effectively to maintain sprinting performance throughout a soccer match when planning a training program.
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