Ask The Expert
Exercise

There used to be ongoing debates about the best time to exercise, and for that matter, it would depend somewhat on whether or not you have type 1 or type 2 diabetes, and whether or not you take insulin, pills, or no diabetes medication--i.e. the obvious concern is potential hypoglycemia if exercising before a meal. Since you didn't specify your diabetes type or treatment, I'll respond with some general information.

Previous thoughts:

• Exercising before breakfast: At one time it was thought that exercising first thing in the morning burned more fat, because allegedly you were without food all night, so the glucose stores were somewhat depleted; furthermore, the argument stated that morning exercise would increase your metabolism for the rest of the day.
• Exercising after a meal: Other experts wrote that exercising after a meal was better because you would increase the burning of those calories, as well as increase your metabolic rate for several hours later.

Current belief:

• Anytime is beneficial: The most recent thinking is that the time of day doesn't matter-it all counts. Again, it would depend somewhat on whether or not you need to be concerned with preventing hypoglycemia-in which case exercising after a meal is better-and/or if you do take diabetes medications that could cause hypoglycemia (i.e. insulin or sulfonylureas) you might need to lower the dose before exercise. If this applies to you, you need to discuss this with your physician.
  • According to the ADA's The Health Professional's Guide to Diabetes and Exercise, your blood glucose can show improvement up to 12-72 hours after an exercise session (depending on the duration and intensity of the exercise). The author concluded that exercise should be performed at the time of day that is most convenient for you, but he also cautioned that because exercise can potentiate the effects of insulin as well as oral diabetes agents, you should be sure to understand hypoglycemia prevention.
  • Here is a quote from an article by Richard Weil, M.Ed., CDE, an exercise physiologist, in an article titled "Exercise Myths and Facts" from Diabetes Self-Management, May/June 2003: (In response to the myth "Exercise in the morning works better than exercise at night"): "Some people believe that if you go to sleep right after exercise you won't get as much benefit from the workout, because your metabolic rate slows down while you're sleeping. If you exercise in the morning, they say, you jump-start your metabolism and burn more calories throughout the day. There's no evidence that this is true." He further states: "The bottom line is that the body responds to exercise whenever you do it…The best time to exercise is the time you are most likely to do it."

So while current research seems to indicate that the time of day doesn't matter, be sure to discuss this with your diabetes team.