2010



Authors

Anna K. Rolleston, Nancy J. Rehrer, Ien J. Hellemans, Elaine Rush, Cheryl Murphy, Benjamin F. Miller

Abstract

Marked energy expenditure, independent of energy balance, could change whole-body protein turnover. The aims of the present study were to determine the effect of participation in a 6-day, 10-stage cycling stage tour on whole-body protein turnover in elite male cyclists, and to determine whether energy and protein turnover are related to fatigue and over-reaching. 13C-leucine was used to determine 18-h whole-body protein turnover in cyclists both before and immediately after a cycling stage race. The 18-h period included two feeding periods to simulate a normal evening meal and a normal breakfast meal, and two fasted periods including overnight. Blood was drawn for the determination of plasma cortisol and serum ferritin on days 2, 4, and 6 and a Profile of Mood States questionnaire was administered on alternate days during the tour event for determination of markers of over-reaching. Mean leucine rate of appearance was unchanged from pre- to post-tour during both fed and fasted conditions and mean energy balance was maintained. Serum ferritin concentration declined and plasma cortisol concentration remained stable over the 6 days. Markers of overtraining were evident in one athlete who pulled out of the tour event due to fatigue on the second to last day. Our main finding was that high energy output over a 6-day period did not significantly change protein turnover during fed, fasted or overnight conditions.

Publication Link

https://onlinelibrary.wiley.com/doi/10.1080/17461391003699054