scholarly journals A Comparison of Isokinetic Knee Strength and Power Output Ratios Between Female Basketball and Volleyball Players

2017 ◽  
Vol 18 (3) ◽  
Author(s):  
Jarosław Kabaciński ◽  
Michał Murawa ◽  
Anna Fryzowicz ◽  
Lechosław Bogdan Dworak
Keyword(s):  
Power Output ◽  
Peak Torque ◽  
Quadriceps Muscle ◽  
Maximal Power ◽  
Basketball Players ◽  
Maximal Power Output ◽  
Squat Jump ◽  
Knee Strength ◽  
Counter Movement Jump ◽  
Volleyball Players

AbstractPurpose. Tests such as the counter movement jump (CMJ) and squat jump (SJ) allow for determining the ratio of maximal power output generated during SJ to CMJ (S/C). The isokinetic peak torque ratio of the hamstrings contracting eccentrically to the quadriceps contracting concentrically (H/Q) is defined as functional H/Q. The purpose of this study was to compare the S/C and functional H/Q between female basketball and volleyball players. Methods. The total of 14 female basketball players (age, 19.8 ± 1.4 years) and 12 female volleyball players (age, 22.3 ± 4.2 years) participated in the study. A piezoelectric force platform was used for the CMJ and SJ. Moreover, isokinetic tests of the hamstrings and quadriceps muscle torque during eccentric and concentric contraction were performed. Results. The results of the S/C and functional H/Q at 90 deg · s

Power output and fatigue of human muscle in maximal cycling exercise

1983 ◽  
Vol 55 (1) ◽  
pp. 218-224 ◽  
Author(s):  
N. McCartney ◽  
G. J. Heigenhauser ◽  
N. L. Jones
Keyword(s):  
Power Output ◽  
Fiber Type ◽  
Average Power ◽  
Lactate Concentration ◽  
Peak Torque ◽  
Muscle Volume ◽  
Thigh Muscle ◽  
Peak Power Output ◽  
Maximal Power ◽  
Maximal Power Output

We studied maximal torque-velocity relationships and fatigue during short-term maximal exercise on a constant velocity cycle ergometer in 13 healthy male subjects. Maximum torque showed an inverse linear relationship to crank velocity between 60 and 160 rpm, and a direct relationship to thigh muscle volume measured by computerized tomography. Peak torque per liter thigh muscle volume (PT, N X ml-1) was related to crank velocity (CV, rpm) in the following equation: PT = 61.7 - 0.234 CV (r = 0.99). Peak power output was a parabolic function of crank velocity in individual subjects, but maximal power output was achieved at varying crank velocities in different subjects. Fiber type distribution was measured in the two subjects showing the greatest differences and demonstrated that a high proportion of type II fibers may be one factor associated with a high crank velocity for maximal power output. The decline in average power during 30 s of maximal effort was least at 60 rpm (23.7 +/- 4.6% of initial maximal power) and greatest at 140 rpm (58.7 +/- 6.5%). At 60 rpm the decline in power over 30 s was inversely related to maximal oxygen uptake (ml X min-1 X kg-1) (r = 0.69). Total work performed and plasma lactate concentration 3 min after completion of 30-s maximum effort were similar for each crank velocity.

Efectos de la Potenciación Post-Activación con cargas de máxima potencia sobre el rendimiento en sprint y cambio de dirección en jugadores de baloncesto (Effects of Post-Activation Potentiation with maximal power loads on Sprint and Change of Direction p

Retos ◽  
2021 ◽  
Vol 41 ◽  
pp. 648-652
Author(s):  
Julio López-Álvarez ◽  
Alberto Sánchez-Sixto
Keyword(s):  
Power Output ◽  
Maximal Power ◽  
Incremental Test ◽  
Basketball Players ◽  
Maximal Power Output ◽  
Warm Up ◽  
Change Of Direction ◽  
Before And After ◽  
Output Load ◽  
First Session

  El objetivo de este estudio fue comprobar el efecto de la realización de una Potenciación Post-Activación (PPA) a través del ejercicio de media sentadilla sobre el rendimiento en sprint y cambio de dirección en jugadores de baloncesto. 12 jugadores de baloncesto participaron en esta investigación realizando dos sesiones. En la primera sesión, realizaron un test incremental de media sentadilla en multipower para conocer la carga con la que generaban la máxima potencia durante la fase concéntrica. En la segunda sesión, tras un calentamiento estandarizado, realizaron los test de sprint (30 m) y cambio de dirección (V-Cut test). Posteriormente, hicieron seis repeticiones de media sentadilla con la carga de máxima potencia de la fase concéntrica obtenida en la primera sesión. Tras cuatro minutos de descanso volvieron a realizar los test de sprint y cambio de dirección. El tiempo en el sprint antes y después de la potenciación fue 4,72 ± 0,25 segundos y 4,71 ± 0,25 segundos, respectivamente. En el V-Cut el tiempo del test antes de la potenciación fue de 8,06 ± 0,44 segundos y tras ella de 7,98 ± 0,38 segundos. El protocolo de PPA basado en la realización de media sentadilla con la carga con la que se desarrolla la máxima potencia durante la fase concéntrica no sirvió como potenciador del rendimiento en sprint y cambio de dirección en jugadores de baloncesto. Abstract. The aim of this study was to determine the effects of a Post-Activation Potentiation (PAP) protocol based on half squat on sprint and change of direction performance. 12 basketball players participated in this investigation performing two sessions. In the first session, participants executed a half squat incremental test in a Smith machine in order to determine maximal power output during the concentric phase. In the second session, after a standardized warm-up, participants performed a sprint test (30 m) and a change of direction test (V-Cut test). After that, the players performed six half squat repetitions with the maximal power output load obtained in the first session. After four minutes rest, they performed the sprint and the change of direction test. Sprint time was 4.72 ± 0.25 s before PAP and 4.71 ± 0.25 s after PAP. V-Cut test was 8.06 ± 0.44 s and 7.98 ± 0.38 s before and after PAP, respectively. A PAP protocol based on half squat with maximal power output during concentric phase load did not serve to enhance sprint and change of direction performance in basketball players.

scholarly journals Aerobic efficiency is associated with the improvement in maximal power output during acute hyperoxia

2017 ◽  
Vol 5 (2) ◽  
pp. e13119 ◽  
Author(s):  
Tom A. Manselin ◽  
Olof Södergård ◽  
Filip J. Larsen ◽  
Peter Lindholm
Keyword(s):  
Power Output ◽  
Maximal Power ◽  
Maximal Power Output

Effect of inspired O2 concentration on leg lactate release during incremental exercise

1996 ◽  
Vol 81 (1) ◽  
pp. 246-251 ◽  
Author(s):  
D. R. Knight ◽  
D. C. Poole ◽  
M. C. Hogan ◽  
D. E. Bebout ◽  
P. D. Wagner
Keyword(s):  
Blood Lactate ◽  
Power Output ◽  
Incremental Exercise ◽  
Venous Blood Flow ◽  
Maximal Power ◽  
Maximal Power Output ◽  
Lactate Accumulation ◽  
Lactate Release ◽  
O2 Concentration ◽  
Blood Lactate Accumulation

The normal rate of blood lactate accumulation during exercise is increased by hypoxia and decreased by hyperoxia. It is not known whether these changes are primarily determined by the lactate release in locomotory muscles or other tissues. Eleven men performed cycle exercise at 20, 35, 50, 92, and 100% of maximal power output while breathing 12, 21, and 100% O2. Leg lactate release was calculated at each stage of exercise as the product of femoral venous blood flow (thermodilution method) and femoral arteriovenous difference in blood lactate concentrations. Regression analysis showed that leg lactate release accounted for 90% of the variability in mean arterial lactate concentration at 20-92% maximal power output. This relationship was described by a regression line with a slope of 0.28 +/- 0.02 min/l and a y-intercept of 1.06 +/- 0.38 mmol/l (r2 = 0.90). There was no effect of inspired O2 concentration on this relationship (P > 0.05). We conclude that during continuous incremental exercise to fatigue the effect of inspired O2 concentration on blood lactate accumulation is principally determined by the rate of net lactate release in blood vessels of the locomotory muscles.

scholarly journals Maximal power output of a stochastic thermodynamic engine

Automatica ◽  
2021 ◽  
Vol 123 ◽  
pp. 109366
Author(s):  
Rui Fu ◽  
Amirhossein Taghvaei ◽  
Yongxin Chen ◽  
Tryphon T. Georgiou
Keyword(s):  
Power Output ◽  
Maximal Power ◽  
Maximal Power Output

Four weeks' corticosteroid inhalation does not augment maximal power output in endurance athletes

2008 ◽  
Vol 42 (11) ◽  
pp. 568-571 ◽  
Author(s):  
H Kuipers ◽  
G A C V. Hullenaar ◽  
B M Pluim ◽  
S E Overbeek ◽  
O De Hon ◽  
...  
Keyword(s):  
Power Output ◽  
Endurance Athletes ◽  
Maximal Power ◽  
Maximal Power Output

scholarly journals Is the Optimal Load for Maximal Power Output During Hang Power Cleans Submaximal?

2020 ◽  
Vol 15 (1) ◽  
pp. 18-24
Author(s):  
Seiichiro Takei ◽  
Kuniaki Hirayama ◽  
Junichi Okada
Keyword(s):  
Power Output ◽  
Peak Power ◽  
Reaction Force ◽  
Strong Positive Correlation ◽  
Maximal Power ◽  
Maximal Power Output ◽  
Success Criterion ◽  
Optimal Load ◽  
Weight Lifters ◽  
Bar Velocity

Purpose: The optimal load for maximal power output during hang power cleans (HPCs) from a mechanical perspective is the 1-repetition-maximum (1RM) load; however, previous research has reported otherwise. The present study thus aimed to investigate the underlying factors that determine optimal load during HPCs. Methods: Eight competitive Olympic weight lifters performed HPCs at 40%, 60%, 70%, 80%, 90%, 95%, and 100% of their 1RM while the ground-reaction force and bar/body kinematics were simultaneously recorded. The success criterion during HPC was set above parallel squat at the receiving position. Results: Both peak power and relative peak power were maximized at 80% 1RM (3975.7 [439.1] W, 50.4 [6.6] W/kg, respectively). Peak force, force at peak power, and relative values tended to increase with heavier loads (P < .001), while peak system velocity and system velocity at peak power decreased significantly above 80% 1RM (P = .005 and .011, respectively). There were also significant decreases in peak bar velocity (P < .001) and bar displacement (P < .001) toward heavier loads. There was a strong positive correlation between peak bar velocity and bar displacement in 7 of 8 subjects (r > .90, P < .01). The knee joint angle at the receiving position fell below the quarter-squat position above 70% 1RM. Conclusions: Submaximal loads were indeed optimal for maximal power output for HPC when the success criterion was set above the parallel-squat position. However, when the success criterion was defined as the quarter-squat position, the optimal load became the 1RM load.

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