Run harder, eat less: High-intensity exercise linked to appetite suppression

My previous post focused on a study suggesting that a sample of the U.S. population is both increasing its physical activity levels as well as getting more obese. Some used this type of data to support the controversial “fit and fat” hypothesis despite pitfalls in the study design and methodology. I would argue that even if this is true, there is a lack of attention being paid to diet, and that people are likely rewarding themselves for moderate physical activity by overeating. After all, a 5K run only burns about 300 calories and isn’t an excuse to gorge on that 500-calorie cookie.

As an appropriate follow-up, this new study from the International Journal of Obesity has found that appetite may be suppressed following a hard workout and you’ll actually eat less.

Seventeen sedentary participants took part in four 30-minute exercise sessions. One consisted of complete rest while the other three involved cycling at either a moderate, high or very high intensity pace. Shortly after completing the exercise, participants were offered as much food (oatmeal) as they wanted. Findings included that their overall food intake was significantly less immediately following the high and very high intensity session. Furthermore, intake/consumption was also decreased for the remainder of the day and on the following day. In short, they consumed significantly less energy following the harder sessions.

So what does this all mean?

Running is well-known to suppress appetite, at least for a while. It seems that the harder the effort, the greater the suppression of appetite, and perhaps for a longer period of time. This is likely attributed to a decrease in hunger hormones as well as a revved-up metabolism following a harder workout.

Hard efforts, whether intervals, tempo running, track repeats or hills, are an important part of any good training program and should be included into your routine a couple of times a week. Be sure to properly refuel following hard efforts by consuming some protein and carbohydrates as well as replacing any lost fluids.

Running can be an excellent tool for those looking to lose – or regulate – weight. But running alone is not the solution. It’s essential that you pay attention to diet, and this must include a basic understanding of how much energy is spent during running (about 100 calories per mile) as well as how much you consume afterwards. But not all miles (or kilometres) are created equal, and harder, faster, higher-intensity running may go further to suppress appetite and prevent overeating.