Early Birds vs. Night Owls: When Is the Best Time to Work Out?

According to a new study about optimal exercise timing, when we exercise—either in the morning or at night—can cause our bodies to respond differently. Although working out any time of the day positively affects our overall health, the timing may help pinpoint which specific benefits we get from regular physical activity. 

Our circadian rhythms are sets of changes in the body that naturally occur over 24 hours. They are connected to many biological functions, including sleep patterns, body temperature, blood pressure, blood sugar, heart rate, hunger, hormone levels and energy balance.

Our circadian rhythms are highly responsive, readjusting to factors like food intake and sleep habits. Recent studies suggest that the time of day we choose to exercise also affects our circadian rhythms, influencing how our bodies and metabolism respond to working out. 

Other factors that could influence your response to exercise may include your hormones, genetic differences, menstrual cycles and your chronotype, which indicates your natural inclination for being awake or asleep at certain times. 

According to the recent study, female participants who exercised in the mornings burned more body fat than their evening exercise counterparts, with much of the fat loss coming from their waistlines. Morning workouts also lowered blood pressure much more effectively than evening workouts.

While morning workouts seemed to help accelerate fat loss, female participants who exercised in the evenings saw increased strength gains. When compared to the morning group, evening exercisers saw their upper body strength improve by approximately 7 percent. The evening group participants could also complete more sit-ups and push-ups than the morning exercisers. 

The study suggested that evening exercise had more health benefits for male participants than working out in the morning. The morning exercise group saw slightly elevated cholesterol levels, but the evening groups lowered theirs significantly. Evening exercisers also burned approximately 28 percent more fat during their workouts, which can lead to body fat loss.