The Best Time of Day to Exercise

Is it better for our bodies to work out at certain times of day?

A useful new study of exercise timing and metabolic health suggests that, at least for some people, the answer is a qualified yes. The study, which looked at men at high risk for Type 2 diabetes, found that those who completed afternoon workouts upped their metabolic health far more than those who performed the same exercise earlier in the day. The results add to growing evidence that when we exercise may alter how we benefit from that exercise.

Scientists have known for some time that the chronology of our days influences the quality of our health. Studies in both animals and people indicate that every tissue in our bodies contains a kind of molecular clock that chimes, in part, in response to biological messages related to our daily exposure to light, food and sleep.

These cellular clocks then help to calibrate when our cells divide, fuel up, express genes and otherwise go about their normal biological work. Tuned by our lifestyles, these clocks create multiple circadian rhythms inside of us that prompt our bodies’ temperatures, hormone levels, blood sugar, blood pressure, muscular strength and other biological