Exercise is an excellent accompaniment to dietary intervention in the pursuit of a healthy/happy weight. There are those “morning people” out there (count me in this group) that exercise early in the morning. Other people wait until the end of the day and a minority of exercisers will do their fitness routines later at night. So, here begs the question: What is the BEST time to exercise?
If the goal is to burn fat stores, exercising in the morning is more favorable for this outcome, as the hormonal peaks of the “fight or flight” hormones occur during the early morning hours. Combining aerobic exercise together with these hormone surges produces more fat burning. Additionally, a study in 2019 published in the Journal of Physiology showed that exercising at or before 7 am resets the biological clock, providing more alertness in the morning/daytime and an earlier sleep. This heightened rest at night allows for the cycle to repeat itself: exercise in the morning and good rest in the evening. Exercise also functions as a stress reducer so the morning exerciser is more prepared to face the daily stress onslaught.
Afternoon exercise requires less energy expenditure because the person usually has eaten some foods unlike the morning exerciser that tends to do this on an empty stomach. Having more energy allows for a more aggressive exercise and better performance so if the person is trying to run faster, bike harder or workout longer, the afternoon exerciser probably holds this advantage.
The bottom line: Exercise at any time is a great component of long-term weight control efforts. However, the morning is probably the best time of the day to exercise. Set that alarm!