Researchers randomly assigned 40 sedentary adults with overweight or obesity to three supervised one-hour walking-plus-resistance-exercise sessions per week either in the morning (8 to 10 a.m.) or evening (5 to 7 p.m.).

After 12 weeks, average cardiovascular fitness and time asleep increased equally in both groups, while body fat, waist size, and calorie intake fell equally in both groups. Both groups also felt less likely to overeat in response to appealing food or emotional stress than when they entered the study.

What to do

Keep in mind that whether and how much you exercise matters more than when you exercise.