The short answer is YES, it does. The body adapts to high-intensity exercise performed regularly at a specific time of day by increasing its work capacity at that time.
Every coach’s ultimate goal is to optimize athletes’ performances on competition day. However, while athletes may be in peak shape on the day of their event, many coaches wonder whether time of day can impact performance. For instance, if a tennis player trains in the evening, will his or her performance in a match be better in the p.m. and worse in the a.m.?
Our bodies have evolved to adapt to a 24-hour circadian rhythmic cycle. That cycle governs when we eat, sleep, work and play. In this study, researchers examined whether training regularly at a particular time of day causes the body to better adapt to high-intensity exercise. In the study, 12 college-age women were broken up into two groups of six, one which trained in the mornings and another that trained in the afternoons. After completion of training, the participants were randomly tested in both the a.m. and p.m. by performing exhaustive cycling sessions. In each session, time to exhaustion and oxygen deficit, a determinant of anaerobic capacity, were measured for each participant.
This study showed that the a.m.- trained group took a longer time to exhaustion in the a.m. than in the p.m. The p.m.- trained group, on the other hand took a longer time to exhaustion when tested in the afternoon.
This study suggests that, in training their athletes for competition, coaches must consider not only the date of competition but also the actual time of day in which it will take place. An athlete’s training program can then be adjusted so that he or she is at peak preparedness at the optimal time of day.
Information for this article came from Hill, Leiferman, Lynch, Dangelmaier, and Burt (1998). “Temporal specificity in adaptations to high-intensity exercise training” Medicine & Science in Sports & Exercise. 30(3):450-455.