Should we be exercising in the morning or afternoon? Before a meal or after a meal? Popular media outlets, researchers, and clinicians seem to love these debates. I hate them. For me, it’s a false dichotomy. A false dichotomy is when people argue two sides as if only one option exists. A winner must be crowned, and a loser exists. But in reality, a gray zone exists, and/or a number of options are available. For me, exercise at any point of the day is a win.
Some but not all research suggests that morning fasted exercise may be the best time of day and condition to work out for weight control and training adaptations. Morning exercise may be a bit better for logistical reasons if you like to get up early. Some of us are indeed early chronotypes who rise early, get as much done as we can, including all our fitness and work-related activities, and then head to bed early (for me that is about 10 PM). Getting an early morning workout seems to fit with our schedules as morning larks.
But if you are a late-day chronotype, early exercise may not be in sync with your low morning energy levels or your preference for leisure-time activities later in the day. And lots of people with diabetes prefer to eat and then exercise. Late chronotypes are less physically active in general compared with early chronotypes, and those who train in the morning tend to have better training adherence and expend more energy overall throughout the day. According to Dr Normand Boulé from the University of Alberta, who presented on the topic of exercise time of day at the recent American Diabetes Association (ADA) Scientific Sessions in San Diego, morning exercise in the fasted state tends to be associated with higher rates of fat oxidation, better weight control, and better skeletal muscle adaptations over time compared with exercise performed later in the day. Dr Boulé also proposed that fasted exercise might be superior for training adaptations and long-term glycemia if you have type 2 diabetes.
Excerpted from Medscape