Should I exercise in the morning or evening?

There has been a lot of debate whether it is more beneficial to workout in the morning or the evening. Balancing daily life and fitting in a workout can be challenging, therefore people want to make the most out of their workouts and know when it benefits them the most. Luckily, a lot of literature has been published about this subject and in this article, we will look at the pros and cons to each workout time.
Morning Workouts
From a logistical perspective, getting your workout done in the morning, before you begin with daily life can be beneficial in the sense that you don’t have to worry about working out later in the day, leaving time to perform other daily tasks.
It’s commonly known that your body releases endorphins so getting that ‘high’ in the morning can be a huge boost for the upcoming day. It has also been found that a morning workout can increase your metabolism. This means you will continue to burn calories throughout the day as you consume them, as opposed to at night while you sleep (1). Furthermore, other literature suggests that exercising in the evening could affect your sleep quality because of your increased body temperature and heart rate following exercise (2). Therefore, working out in the morning rather than the evening may improve sleep duration and quality.
Moreover, a study by Gonzalez and colleagues found that people exercising on an empty stomach in the morning can burn up to 20% more body fat compared to those exercising on a full stomach in the evening (3).
Evening/Night Workouts
This seems to be the most popular workout time for the general popular. Working out in the evening has its obvious advantages, such as extra sleep in the morning, but it also has many other benefits.
It has been found that in the evening your body temperature is increased compared to in the morning, this optimises muscle function, enzyme activity and endurance which improves exercise performance overall (4). Between the hours of 2-6pm, your body temperature is at its highest, this may mean that you will be exercising during the window of time your body is most ready, potentially making it the most effective time of day to work out.
Reaction time has also been found to be optimal in the evening rather than in the morning, this can benefit performance in intense exercises such as HIIT and circuit training (5). Additionally, oxygen kinetics are faster in the evening, this can benefit your performance as you will use up your energy stores more slowly and effectively.
So, when is the best time? That is completely up to you! For the majority of people, the timing should be when you feel comfortable working out and when you can fit in into your schedule. By keeping your workouts consistent and continuously progressing your workouts, timings shouldn’t be a major concern.
1) Hanlon, B., Larson, M. J., Bailey, B. W., & Lecheminant, J. D. (2012). Neural response to pictures of food after exercise in normal-weight and obese women. Medicine and science in sports and exercise, 44(10), 1864-1870.
2) Fairbrother, K., Cartner, B., Alley, J. R., Curry, C. D., Dickinson, D. L., Morris, D. M., & Collier, S. R. (2014). Effects of exercise timing on sleep architecture and nocturnal blood pressure in prehypertensives. Vascular health and risk management, 10, 691.
3) Gonzalez, J. T., Veasey, R. C., Rumbold, P. L., & Stevenson, E. J. (2013). Breakfast and exercise contingently affect postprandial metabolism and energy balance in physically active males. British Journal of Nutrition, 110(4), 721-732.
4) Racinais, S. (2010). Different effects of heat exposure upon exercise performance in the morning and afternoon. Scandinavian journal of medicine & science in sports, 20, 80-89.
5) Hines, C. B. (2004). Time-of-day effects on human performance. Journal of Catholic Education, 7(3), 390-413.