Effect of training on muscle metabolism during treadmill sprinting.
Sixteen subjects volunteered for the study and were divided into a control (4 males and 4 females) and experimental group (4 males and 4 females, who undertook 8 wk of sprint training). All subjects completed a maximal 30-s sprint on a nonmotorized treadmill and a 2-min run on a motorized treadmill at a speed designed to elicit 110% of maximum oxygen uptake (110% run) before and after the period of training. Muscle biopsies were taken from vastus lateralis at rest and immediately after exercise. The metabolic responses to the 110% run were unchanged over the 8-wk period. However, sprint training resulted in a 12% (P less than 0.05) and 6% (NS) improvement in peak and mean power output, respectively, during the 30-s sprint test. This improvement in sprint performance was accompanied by an increase in the postexercise muscle lactate (86.0 +/- 26.4 vs. 103.6 +/- 24.6 mmol/kg dry wt, P less than 0.05) and plasma norepinephrine concentrations (10.4 +/- 5.4 vs. 12.1 +/- 5.3 nmol/l, P less than 0.05) and by a decrease in the postexercise blood pH (7.17 +/- 0.11 vs. 7.09 +/- 0.11, P less than 0.05). There was, however, no change in skeletal muscle buffering capacity as measured by the homogenate technique (67.6 +/- 6.5 vs. 71.2 +/- 4.5 Slykes, NS).
Nevill
M E
ME
Department of Physical Education and Sports Science, University of Technology, Loughborough, United Kingdom.
Boobis
L H
LH
Brooks
S
S
Williams
C
C
D000328:Adult; D004837:Epinephrine / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D009132:Muscles / Q000378:metabolism*; D009638:Norepinephrine / Q000097:blood; D010806:Physical Education and Training; D012420:Running
D009638:Norepinephrine; D004837:Epinephrine