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.
Human Performance Laboratories, The University of Memphis, Memphis, Tennessee 38152, USA. afry@memphis.edu
Andrew C
AC
Fry
Jesse M
JM
Webber
Lawrence W
LW
Weiss
Matthew P
MP
Harber
Mark
M
Vaczi
Nancy A
NA
Pattison
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