Popular opinion is that working out makes you hungrier, increases your appetite as your body craves nutrients that it can use to recover. But the opposite may also be true if a recent British study has it right. Research, published in Medicine & Science in Sports & Exercise, posits that exercising actually suppresses the appetite.
Two separate studies were conducted in the UK where researchers studied the effects of exercise before meals on appetite, and whether it indeed helps boost appetite among individuals.
First a team of researchers at Loughborough University studied the hormonal, psychological and behavioral responses of 12 slim, healthy females over a nine-hour period after restricting their calorie intake. Their levels of ghrelin or the hunger hormone were found to have increased, while levels of peptide YY, a hormone that kills hunger, had dropped. As a result, this group consumed 944 calories on an average at a test buffet meal, compared with the 660 calorie average for participants in whom a calorie deficit – where the body has burnt more calories than it consumed – was created with a treadmill run.
In the second study, 10 men and 10 women were asked to run for 60 minutes and were monitored for seven hours afterwards. Among this group, the more vigorous the workouts, the more hunger was suppressed, according to the study. Popular wisdom would suggest that they would get hungrier as the intensity of the exercise increased, especially when it comes to aerobic exercises such as running.
These studies show the way for future research on the subject of exercise and appetite or hunger suppression. What needs to be studied now is the long-term – relatively speaking – effects of exercise and hunger among subjects. This particular research was restricted to the immediate effects of exercise i.e within the next few hours. Researchers will look at studying the effects in a 24-hour cycle next to see whether this seemingly ignored benefit of working out can be applied to practical needs such as weight loss or building muscles.