scholarly journals Jump height is a poor indicator of lower limb maximal power output: theoretical demonstration, experimental evidence and practical solutions

2018 ◽  
Author(s):  
Jean-Benoit Morin ◽  
Pedro Jiménez-Reyes ◽  
Matt Brughelli ◽  
Pierre Samozino

Lower limb maximal power output (Pmax) is a key physical component of performance in many sports. During squat jump (SJ) and countermovement jump (CMJ) tests, athletes produce high amounts of mechanical work over a short duration to displace their body mass (i.e. the dimension of mechanical power). Thus, jump height has been frequently used by the sports science and medicine communities as an indicator of Pmax. However, in this article, we contended that SJ and CMJ height are in fact poor indicators of Pmax in trained populations. To support our opinion, we first detailed why, theoretically, jump height and Pmax are not fully related. Specifically, we demonstrated that individual body mass, distance of push-off, optimal loading and force-velocity characteristics confound the jump height-Pmax relationship. We also discussed the poor relationship between SJ or CMJ height and Pmax measured with a force plate based on data reported in the literature, which added to our own experimental evidence.Finally, we discussed the limitations of existing practical solutions (regression-based estimation equations and allometric scaling), and advocated using a valid, reliable and simple field-based procedure to compute individual Pmax directly from jump height, body mass and push-off distance. The latter may allow researchers and practitioners to reduce bias in their assessment of Pmax by using jump height as an input with a simple yet accurate computation method, and not as the first/only variable of interest.

2017 ◽  
Vol 38 (14) ◽  
pp. 1083-1089 ◽  
Author(s):  
Johnny Padulo ◽  
Gian Migliaccio ◽  
Luca Ardigò ◽  
Bruno Leban ◽  
Marco Cosso ◽  
...  

AbstractThe aim was to compare lower-limb power, force, and velocity capabilities between squat and leg press movements. Ten healthy sportsmen performed ballistic lower-limb push-offs against 5-to-12 different loads during both the squat and leg press. Individual linear force-velocity and polynomial power-velocity relationships were determined for both movements from push-off mean force and velocity measured continuously with a pressure sensor and linear encoder. Maximal power output, theoretical maximal force and velocity, force-velocity profile and optimal velocity were computed. During the squat, maximal power output (17.7±3.59 vs. 10.9±1.39 W·kg−1), theoretical maximal velocity (1.66±0.29 vs. 0.88±0.18 m·s−1), optimal velocity (0.839±0.144 vs. 0.465±0.107 m·s−1), and force-velocity profile (−27.2±8.5 vs. −64.3±29.5 N·s·m−1·kg−1) values were significantly higher than during the leg press (p=0.000, effect size=1.72–3.23), whereas theoretical maximal force values (43.1±8.6 vs. 51.9±14.0 N·kg−1, p=0.034, effect size=0.75) were significantly lower. The mechanical capabilities of the lower-limb extensors were different in the squat compared with the leg press with higher maximal power due to much higher velocity capabilities (e.g. ability to produce force at high velocities) even if moderately lower maximal force qualities.


2017 ◽  
Vol 12 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Pedro Jiménez-Reyes ◽  
Pierre Samozino ◽  
Fernando Pareja-Blanco ◽  
Filipe Conceição ◽  
Víctor Cuadrado-Peñafiel ◽  
...  

Purpose:To analyze the reliability and validity of a simple computation method to evaluate force (F), velocity (v), and power (P) output during a countermovement jump (CMJ) suitable for use in field conditions and to verify the validity of this computation method to compute the CMJ force–velocity (F–v) profile (including unloaded and loaded jumps) in trained athletes.Methods:Sixteen high-level male sprinters and jumpers performed maximal CMJs under 6 different load conditions (0–87 kg). A force plate sampling at 1000 Hz was used to record vertical ground-reaction force and derive vertical-displacement data during CMJ trials. For each condition, mean F, v, and P of the push-off phase were determined from both force-plate data (reference method) and simple computation measures based on body mass, jump height (from flight time), and push-off distance and used to establish the linear F–v relationship for each individual.Results:Mean absolute bias values were 0.9% (± 1.6%), 4.7% (± 6.2%), 3.7% (± 4.8%), and 5% (± 6.8%) for F, v, P, and slope of the F–v relationship (SFv), respectively. Both methods showed high correlations for F–v-profile-related variables (r = .985–.991). Finally, all variables computed from the simple method showed high reliability, with ICC >.980 and CV <1.0%.Conclusions:These results suggest that the simple method presented here is valid and reliable for computing CMJ force, velocity, power, and F–v profiles in athletes and could be used in practice under field conditions when body mass, push-off distance, and jump height are known.


2011 ◽  
Vol 27 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Jeroen Vrints ◽  
Erwin Koninckx ◽  
Marc Van Leemputte ◽  
Ilse Jonkers

Saddle position affects mechanical variables during submaximal cycling, but little is known about its effect on mechanical performance during maximal cycling. Therefore, this study relates saddle position to experimentally obtained maximal power output and theoretically calculated moment generating capacity of hip, knee and ankle muscles during isokinetic cycling. Ten subjects performed maximal cycling efforts (5 s at 100 rpm) at different saddle positions varying ± 2 cm around the in literature suggested optimal saddle position (109% of inner leg length), during which crank torque and maximal power output were determined. In a subgroup of 5 subjects, lower limb kinematics were additionally recorded during submaximal cycling at the different saddle positions. A decrease in maximal power output was found for lower saddle positions. Recorded changes in knee kinematics resulted in a decrease in moment generating capacity of biceps femoris, rectus femoris and vastus intermedius at the knee. No differences in muscle moment generating capacity were found at hip and ankle. Based on these results we conclude that lower saddle positions are less optimal to generate maximal power output, as it mainly affects knee joint kinematics, compromising mechanical performance of major muscle groups acting at the knee.


Author(s):  
Jozo Grgic ◽  
Sandro Venier ◽  
Pavle Mikulic

Purpose: To compare the acute effects of caffeine and placebo ingestion with a control condition (ie, no supplementation) on vertical jump performance. Methods: The sample for this study consisted of 26 recreationally trained men. Following the familiarization visit, the subjects were randomized in a double-blind manner to 3 main conditions: placebo, caffeine, and control. Caffeine was administered in the form of a gelatin capsule in the dose of 6 mg·kg body weight−1. Placebo was also administered in the form of a gelatin capsule containing 6 mg·kg−1 of dextrose. Vertical jump performance was assessed using a countermovement jump performed on a force platform. Analyzed outcomes were vertical jump height and maximal power output. Results: For vertical jump height, significant differences were observed between placebo and control conditions (g = 0.13; 95% confidence interval [CI], 0.03–0.24; +2.5%), caffeine and control conditions (g = 0.31; 95% CI, 0.17–0.50; +6.6%), and caffeine and placebo conditions (g = 0.19; 95% CI, 0.06–0.34; +4.0%). For maximal power output, no significant main effect of condition (P = .638) was found. Conclusions: Ingesting a placebo or caffeine may enhance countermovement jump performance compared with the control condition, with the effects of caffeine versus control appearing to be greater than the effects of placebo versus control. In addition, caffeine was ergogenic for countermovement jump height compared with placebo. Even though caffeine and placebo ingestion improved vertical jump height, no significant effects of condition were found on maximal power output generated during takeoff.


Author(s):  
Sarah A. Manson ◽  
Cody Low ◽  
Hayley Legg ◽  
Stephen D. Patterson ◽  
César Meylan

AbstractExplosive actions are integral to soccer performance and highly influenced by the ability to generate maximal power. The purpose of this study was to investigate the relationship between force-velocity profile, jump performance, acceleration and maximal sprint speed in elite female soccer players. Thirty-nine international female soccer players (24.3±4.7 years) performed 40-m sprints, maximal countermovement jumps and five loaded squat jumps at increasing loads to determine individual force-velocity profiles. Theoretical maximal velocity, theoretical maximal force, maximal power output, one repetition maximal back squat and one repetition maximal back squat relative to body mass were determined using the force-velocity profile. Counter movement jump, squat jump and maximal power output demonstrated moderate to large correlation with acceleration and maximal sprint speed (r=− 0.32 to −0.44 and −0.32 to −0.67 respectively, p<0.05). Theoretical maximal velocity and force, one repetition maximal and relative back squat demonstrated a trivial to small relationship to acceleration and maximal sprint speed (p>0.05). Vertical force-velocity profiling and maximal strength can provide valuable insight into the neuromuscular qualities of an athlete to individualize training, but the ability to produce force, maximal power, and further transference into sprint performance, must be central to program design.


1983 ◽  
Vol 55 (1) ◽  
pp. 218-224 ◽  
Author(s):  
N. McCartney ◽  
G. J. Heigenhauser ◽  
N. L. Jones

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.


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

1996 ◽  
Vol 81 (1) ◽  
pp. 246-251 ◽  
Author(s):  
D. R. Knight ◽  
D. C. Poole ◽  
M. C. Hogan ◽  
D. E. Bebout ◽  
P. D. Wagner

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.


Sign in / Sign up

Export Citation Format

Share Document