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Power outputs of a machine squat-jump across a spectrum of loads.
J Strength Cond Res. 2007 Nov; 21(4):1260-4.JS

Abstract

The load that maximizes mechanical power output (Pmax) has received considerable research attention owing to its perceived importance to training prescription. However, it may be that identifying Pmax is of little importance if the difference in power output about Pmax is insubstantial. Additionally, comparing the effect of load on power output between studies is problematic due to various methodological differences. The purpose of this study therefore was to quantify the concentric power output for a machine squat-jump across a spectrum of loads (10-100% of 1 repetition maximum [1RM]). To estimate Pmax load and proximate loads a quadratic was fitted to the power output (Watts) and load (% of 1RM) of 18 well-trained rugby athletes. Pmax for peak and mean power output occurred at 21.6 +/- 7.1% of 1RM (mean +/- SD) and 39.0 +/- 8.6% of 1RM, respectively. A 20% change in load either side of the maximum resulted in a mean decrease of only 9.9% (90% confidence limits +/-2.4%) and 5.4% (+/-0.9%) in peak and mean power respectively; standard deviations about these means (representing individual differences in the decrease) were 6.0% and 2.1%, respectively (90% confidence limits x//1.34). It appears that most athletes have a broad peak in their power profile for peak or mean power. The preoccupation of identifying one load for maximizing power output would seem less meaningful than many practitioners and scientists believe.

Authors+Show Affiliations

Institute of Sport and Recreation Research New Zealand, Auckland University of Technology, Auckland, New Zealand. nigel.harris@aut.ac.nzNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Randomized Controlled Trial
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

18076258

Citation

Harris, Nigel K., et al. "Power Outputs of a Machine Squat-jump Across a Spectrum of Loads." Journal of Strength and Conditioning Research, vol. 21, no. 4, 2007, pp. 1260-4.
Harris NK, Cronin JB, Hopkins WG. Power outputs of a machine squat-jump across a spectrum of loads. J Strength Cond Res. 2007;21(4):1260-4.
Harris, N. K., Cronin, J. B., & Hopkins, W. G. (2007). Power outputs of a machine squat-jump across a spectrum of loads. Journal of Strength and Conditioning Research, 21(4), 1260-4.
Harris NK, Cronin JB, Hopkins WG. Power Outputs of a Machine Squat-jump Across a Spectrum of Loads. J Strength Cond Res. 2007;21(4):1260-4. PubMed PMID: 18076258.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Power outputs of a machine squat-jump across a spectrum of loads. AU - Harris,Nigel K, AU - Cronin,John B, AU - Hopkins,Will G, PY - 2007/12/14/pubmed PY - 2008/11/4/medline PY - 2007/12/14/entrez SP - 1260 EP - 4 JF - Journal of strength and conditioning research JO - J Strength Cond Res VL - 21 IS - 4 N2 - The load that maximizes mechanical power output (Pmax) has received considerable research attention owing to its perceived importance to training prescription. However, it may be that identifying Pmax is of little importance if the difference in power output about Pmax is insubstantial. Additionally, comparing the effect of load on power output between studies is problematic due to various methodological differences. The purpose of this study therefore was to quantify the concentric power output for a machine squat-jump across a spectrum of loads (10-100% of 1 repetition maximum [1RM]). To estimate Pmax load and proximate loads a quadratic was fitted to the power output (Watts) and load (% of 1RM) of 18 well-trained rugby athletes. Pmax for peak and mean power output occurred at 21.6 +/- 7.1% of 1RM (mean +/- SD) and 39.0 +/- 8.6% of 1RM, respectively. A 20% change in load either side of the maximum resulted in a mean decrease of only 9.9% (90% confidence limits +/-2.4%) and 5.4% (+/-0.9%) in peak and mean power respectively; standard deviations about these means (representing individual differences in the decrease) were 6.0% and 2.1%, respectively (90% confidence limits x//1.34). It appears that most athletes have a broad peak in their power profile for peak or mean power. The preoccupation of identifying one load for maximizing power output would seem less meaningful than many practitioners and scientists believe. SN - 1533-4287 UR - https://www.unboundmedicine.com/medline/citation/18076258/Power_outputs_of_a_machine_squat_jump_across_a_spectrum_of_loads_ DB - PRIME DP - Unbound Medicine ER -