Does Exercise Timing Matter?
Chances are, you’re recommending exercise to almost all of your patients. Exercise promotes healthy weight, mood, and more. But did you ever consider whether the timing of exercise matters?
In a study published in the Fall of 2019, researchers asked whether exercising in a fasting state produces any greater benefits than exercising in a fed state. To find out, they randomized a group of overweight or obese men to exercise before breakfast, after breakfast, or not at all.
Over the 6-week trial, the men in both exercise groups lost more weight than the men in the control group. The amount of weight loss was similar for both exercise groups. On a surface level, it would appear that the timing of exercise didn’t matter. However, there were meaningful differences between the groups in other health parameters.
The men who exercised before breakfast burned double the amount of fat during exercise as those who exercised after breakfast. They also benefited from reduced spikes in insulin after meals and improved insulin sensitivity. The muscles in men who exercised before breakfast showed increases in GLUT4, a key protein required for the transport of glucose into muscle cells.
This study offers compelling evidence that overweight or obese men might be able to achieve more health benefits with the same investment of time and energy by exercising before breakfast. Future studies will need to determine whether the same is true for women or people who are already a healthy weight.