If you want to lose or maintain weight, improve your fat-burning capacity, and lower blood glucose levels, exercise in the morning on an empty stomach. I’ve mentioned this before, but a new study from Belgium reinforces that premise. Gretchen Reynolds of the New York Times (one of my favorite fitness writers) cites the study, published recently in the Journal of Physiology. For this study, researchers recruited 28 healthy, active young men, and began feeding them an unhealthy diet consisting of 50% fat and 30% more calories, overall, than they had been consuming. Some of the men agreed not to exercise during the study, the others were split into two exercise groups. Both of the exercise routines were similar; high intensity and physically exhausting. They worked out four times per week, from 60 to 90 minutes. The control group and one of the exercise groups ate a carbohydrate-rich breakfast before exercise, the other exercise group only had water. After exercise, they too ate a similar breakfast.
The experiment lasted six weeks, and the control group, to no ones surprise, gained, on average, six pounds. They had also developed insulin resistance, meaning their muscles were not as efficient removing glucose (sugar) from the bloodstream (insulin resistance is a precursor to type 2 diabetes). The men who ate breakfast before exercise gained weight too, about half of what the non-exercising group did. They too were showing signs of insulin resistance and were storing greater amounts of fat in their muscles. The group that exercised before breakfast gained almost no weight, even at caloric and fat intake levels far above health recommendations. This group also burned fat more efficiently, and their muscles were able to keep blood sugar levels in the good range.
Conclusions reached in this study are: exercising in a fasted state improves one’s metabolic profile and maintained weight-even with a gluttonous diet. If your New Years resolution is to lose weight and get healthier, I’d recommend exercising early in the day in a fasted state. Also, remember the exercise needs to be vigorous.
Happy New Year!
Stay well, John R Blilie, M.S.