Studies examining the effect
of time of day on exercise have shown varying results and responses to exercise.
In some cases, there may be a slight difference that is statistically insignificant.
One study has reported that
while exercise-induced elevations of temperature were higher in the early morning
than at other times of day, this increase was not statistically significant.
Exercising in the afternoon
has been shown to affects anaerobic capacity. Anaerobic capacity has been shown
to be significantly higher, by 26%, in the afternoon than in the morning.
In contrast, maximal aerobic
exercise does not appear to be affected by time of day. In the same study examining
anaerobic capacity, maximal aerobic capacity was higher in the afternoon, but
this difference was not statistically significant. Another study also demonstrated
that maximal aerobic capacity was not statistically different in the morning versus
the afternoon.
No effect of the time of
day for running has been shown on the body's anxiety responses - state anxiety,
perceived exertion, heart rate, temperature and blood.
Rectal temperature and heart
rate were lower in the morning than in the evening. Sweat onset occurred sooner
at 08:30 h compared to 17:30 h. Time to exhaustion did not vary with time of day.