Muscle fiber characteristics of competitive power lifters

J Strength Cond Res. 2003 May;17(2):402-10. doi: 10.1519/1533-4287(2003)017<0402:mfcocp>2.0.co;2.

Abstract

To examine the skeletal muscle characteristics of power lifters, 5 competitive power lifters (PL; X +/- SE; age = 31.0 +/- 1.5 years, squat = 287.7 +/- 15.7 kg, bench press = 170.5 +/- 17.7 kg, and deadlift = 284.2 +/- 7.5 kg) and 5 untrained control subjects (CON; age = 27.3 +/- 3.3 years) served as subjects. Isokinetic squat force and power was greater (p < 0.05) for the PL at all bar velocities (0.20, 0.82, and 1.43 m;pd s(-1)), as was vertical jump height and estimated power. Muscle biopsies from the vastus lateralis m. revealed significant differences for percent fiber type (PL, IIA = 45.5 +/- 1.6%, IIB = 1.3 +/- 0.8%; CON, IIA = 33.4 +/- 3.1%, IIB = 12.0 +/- 2.4%); percent fiber type area (PL, IIA = 51.8 +/- 1.6%, IIB = 1.3 +/- 0.8%; CON, IIA = 43.5 +/- 3.4%, IIB = 12.4 +/- 2.6%); and percent myosin heavy chain isoform (PL, IIa = 59.5 +/- 6.1%; CON, 46.5 +/- 2.5%). Muscle fiber characteristics were significantly correlated (r = +/- 0.61) with numerous strength and power measures for the PL. These data illustrate the muscle fiber characteristics necessary for the maximal force production requirements of power lifting.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Analysis of Variance
  • Anthropometry
  • Biopsy, Needle
  • Humans
  • Immunohistochemistry
  • Male
  • Muscle Contraction / physiology
  • Muscle Fatigue*
  • Muscle Fibers, Skeletal / pathology*
  • Muscle Fibers, Skeletal / physiology
  • Muscle Relaxation / physiology
  • Muscle, Skeletal / pathology*
  • Muscle, Skeletal / physiology
  • Myosin Heavy Chains / ultrastructure
  • Physical Endurance
  • Probability
  • Reference Values
  • Sensitivity and Specificity
  • Weight Lifting / physiology*

Substances

  • Myosin Heavy Chains