There may be an optimal time for swimming performance: Olympic swimmers clock faster times at 5 p.m., according to research from Stanford University circadian biologist Renske Lok, PhD, and an international team of scientists. Lok et al. analyzed Olympic swim times of 72 female and 72 male swimmers between 2004 and 2016. Data analysis showed that time of day strongly affected performance, with fastest times occurring around 5:12 p.m.—a 0.32% improvement relative to 8 a.m. Although this amounts to fractions of seconds, for swimmers it can mean the difference between a gold medal and a bronze.

Study authors suggest that, to take advantage of this effect and choose the right time for swimming, athletes could wake up earlier or later to adapt their potential for peak performance to the time of the final competition. Personal trainers may want to explore this concept in an effort to fine-tune a client’s program.

The study is available in Scientific Reports (2020; 10 [16088]).

See also: Mind-Body Pool Fitness