Some people are morning exercisers. For them, an early run or swim is as much a part of their wake-up ritual as that first cup of coffee. Others can’t abide by the idea. They need a nighttime workout to rid themselves of the day’s stresses.
Does it make a difference? Several recent studies suggest that it does. But it’s complicated.
One recent paper indicates that morning exercise may activate certain genes in the muscle cells, boosting their ability to metabolize sugar and fat. While scientists say this finding requires further study, they think it ultimately might help those who are overweight or suffering from Type 2 diabetes.
The researchers looked at the changes in muscle tissues after morning workouts, specifically the glucose breakdown and fat burning. In analyzing the tissue, they found that exercise seemed to provide the most beneficial effects on metabolism during the mouse equivalent of what would be late morning for humans.
“We identified that time of exercise is critical in order for exercise to be beneficial” in metabolizing sugar and fat, Sassone-Corsi said.
Sassone-Corsi believes this is controlled by a process that relies on a specific protein, HIF1-alpha, which directly regulates the body’s circadian clock, the internal mechanism that influences human cycles of sleep, awakening, and eating, among other things.
“Exercising late at night may interfere with sleep as it tends to energize you and enhance alertness, although some people like to exercise at the end of the day to help relieve the stresses of the day and prepare for evening activities, which is fine,” says Edward R. Laskowski, co-director of the Mayo Clinic Sports Medicine and professor in the department of physical medicine and rehabilitation. “Morning exercise has the advantage that no matter what else happens during the day, you have incorporated your physical activity. It also increases alertness and helps cognitive functioning.”
The research “tends to suggest that morning exercising before eating is helpful in terms of ensuring or maximizing some of the positives effects of exercise on metabolism,” he says. “To me, the other positive of exercising first thing is that you get it done before the day catches up with you.”
But the most important thing — as a well-known athletic shoe company used to say in its advertising — is to just do it, regardless of when.