Effect of High-intensity Exercise Training on Functional Capacity of Limb Skeletal Muscle
Format of Original
American Physiological Society
Journal of Applied Physiology
Original Item ID
The purpose of this study was to determine whether a program of regular sprint exercise training alters the functional properties or protects against the development of fatigue in fast- and slow-twitch rat skeletal muscle. The training program consisted of 6 sprints of 4.5-min duration at 40 m/min and 15% slope with 2.5-min rest intervals, performed 5 days/wk for 6 wk. The exercise program significantly increased (P-1·min-1) in the predominantly type I soleus (SOL) from 28 ± 2 to 44 ± 2; the type IIb superficial region of the vastus lateralis (SVL) from 10 ± 1 to 16 ± 1; and the type IIa deep region of the vastus lateralis (DVL) from 34 ± 2 to 53 ± 2. Phosphofructokinase activity (µmol·g-1·min-1) also increased with training in the SOL (17 ± 1 vs. 23 ± 1) and the DVL (64 +/- 5 vs. 79 +/- 5). Sprint training reduced (P less than 0.05) the contraction time (CT) (111 +/- 7 vs. 92 +/- 3 ms) and the one-half relaxation time (118 ± 3 vs. 104 ± 2 ms) in the slow-twitch soleus. The exercise program also induced a decreased CT in the fast-twitch extensor digitorum longus (EDL), but significance was limited to the P < 0.1 level. Muscle fatigue was produced by electrical stimulation at 45 trains/min and either 15 trains/min in SOL or 10 trains/min in the EDL and SVL for 1, 5, or 10 min.(ABSTRACT TRUNCATED AT 250 WORDS)
Troup, John Patrick; Metzger, Joseph Mark; and Fitts, Robert H., "Effect of High-intensity Exercise Training on Functional Capacity of Limb Skeletal Muscle" (1986). Biological Sciences Faculty Research and Publications. 477.