A circadian rhythm is any biological process that displays an endogenous, en trainable oscillation of about 24 hours. These 24-hour rhythms are driven by a circadian clock, and they have been widely observed in plants as well as animals. Although circadian rhythms are endogenous and self-sustained, they are adjusted to the local environment by external cues, commonly the most important of which is daylight.
An athlete’s performance is regulated by various factors and one of the most important is circadian rhythms. A recent study looked into the importance for athletes to be aware of sleep cycle as well as leave time for the purpose of adjusting to travel needs for competitions.
The researchers used a novel test to characterize the circadian phenotypes of more than 120 athletes. Then, the study looked into the fitness levels of 20 athletes of the same age group. They were asked to take part in tests that looked into their cardiovascular endurance at different times of the day. The participants belonged to three circadian types: early, intermediate and late, each contributing to 28, 48 and 24 % of the population of participants, respectively.
Their results showed that in the earlier tests, the early phenotypes gave the best athletic performance, which was followed by the intermediates. The late phenotypes’ performance peaked in the later part of the day. During the day, the early and the intermediate phenotypes showed a variation of about 7-10 % with regards to their physical performance, while that of the late phenotypes varied up to 26 %.
The original paper can be accessed here.