Journal of Applied Physiology, Vol 61, Issue 1 30-36, Copyright © 1986 by American Physiological Society
Specificity of leg power changes to velocities used in bicycle endurance training
K. Rosler, K. E. Conley, H. Howald, C. Gerber and H. Hoppeler
Increases in leg power production resulting from 8 wk of bicycle endurance
training (30 min/day, 5 times/wk) were studied using an isokinetic
dynamometer. In addition, biopsies of vastus lateralis were analyzed to
characterize muscle ultrastructural changes. Performance increased on the
dynamometer specifically near the estimated average knee angular velocity
used during the bicycle training (200 degrees/s). Power measurements were
made during the first 5 contractions (maximal power: Pmax) and last 5
contractions (final power: Pend) of 25 and 50 consecutive contractions (at
60 and 240 degrees/s, respectively). Pmax and Pend increased only at 240
degrees/s but not at 60 degrees/s. These increases in Pmax (86 W) and Pend
(78 W) resulted primarily from longer torque maintenance but also from
increased peak torque during each contraction and were close to the
increase in mechanical power output maintained on the bicycle (Pb; 78 W)
during the training sessions. The specificity of these changes to the
angular velocities used in the bicycle training indicates a neural basis to
these adaptations. We suggest that these neural adaptations, coupled with
the observed enhancement of muscle mitochondrial and capillary density (+41
and +15%, respectively) underlie the increased ability to maintain power
production on a bicycle after endurance training.
