Muscle fiber characteristics of competitive power lifters.
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.
Fry
Andrew C
AC
Human Performance Laboratories, The University of Memphis, Memphis, Tennessee 38152, USA. afry@memphis.edu
Webber
Jesse M
JM
Weiss
Lawrence W
LW
Harber
Matthew P
MP
Vaczi
Mark
M
Pattison
Nancy A
NA
D000328:Adult; D000704:Analysis of Variance; D000886:Anthropometry; D001707:Biopsy, Needle; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018763:Muscle Fatigue; D018485:Muscle Fibers, Skeletal / Q000473:pathology* / Q000502:physiology; D009126:Muscle Relaxation / Q000502:physiology; D018482:Muscle, Skeletal / Q000473:pathology* / Q000502:physiology; D018995:Myosin Heavy Chains / Q000648:ultrastructure; D010807:Physical Endurance; D011336:Probability; D012016:Reference Values; D012680:Sensitivity and Specificity; D014891:Weight Lifting / Q000502:physiology*
D018995:Myosin Heavy Chains