Exercise helps burn calories, and that calorie burning continues even when you aren’t training. In an interesting finding, researchers from Brigham and Women’s Hospital and Harvard Medical School determined the rate of calorie burning at rest fluctuates throughout the day. The study was published in the journal Current Biology.

To measure their metabolic rate independent of activity and food consumption, subjects lived in a room without clocks or windows and slept during specific times that were adjusted 4 hours later each day. This forced their internal circadian clock to operate at its own pace.

Resting energy expenditure was lowest late at night when there is a slight drop in core body temperature. Energy expenditure when your body is at rest is typically highest in the afternoon and early evening.