COLUMBIA, S.C., Feb. 28 (UPI) -- Swimming performance had significant circadian variation when expressed relative to the time of day, according to a U.S. study.
Specifically, swim performance was impaired between 2:00 a.m. and 8:00 a.m., compared to all other times of day -- peak performance was at 11:00 p.m., found the researchers at the University of South Carolina, Columbia.
Circadian rhythms are generated within the body and are reset almost every 24 hours. Human circadian rhythms originate from the tiny hypothalamus residing in the back of the brain. The hypothalamus, working with the endocrine system, drives many of our behavioral and physiological rhythms.
The data suggest a circadian rhythm in athletic performance exists. The circadian range from best to worst performance in this study -- 5.84 seconds -- could have considerable importance in athletic competition such as swimming.
The findings are published in the Journal of Applied Physiology.
