A recent study out of the University of Western Australia found that high-intensity exercises may suppress appetite briefly afterward. The team conducting the research discovered that overweight, sedentary men (having a body mass index, or BMI, of 25-29.9) consumed almost two-hundred fewer calories after performing a vigorous exercise routine than after a period of rest.
Previous research that looked at high-intensity exercise and its effects on the body suggest that it correlates with appetite control and alterations in specific hormones that manage your feelings of hunger and your level of fullness. However, this new research that just came out discovered that those hormones are affected in different ways based on the type of workout regimen--continuous versus intermittent, and different intensity levels (moderate-, high- and very-high-intensity exercises).
The participants of the study went through four 30-minute workouts. One session was a period of rest, to serve as the control. In the other three exercise sessions, the participants worked out on a stationary bike at various levels of intensity. During one session, the men cycled continuously at a moderate level of intensity. The other two sessions involved intermittent exercise at either high-intensity or very-high-intensity where they would alternate between quick bursts of high-speed pedaling followed by longer bouts of cycling at a slower speed.
After exercising (or resting), the men consumed a 267-calorie liquid meal and were also asked to eat oatmeal until they became full. The results: the participants consumed fewer calories following the intermittent high-intensity and intermittent very-high-intensity exercise sessions versus the period of rest. Here is the calorie breakdown of what the men consumed after each session:
After a period of rest: 764 calories consumed
After continuous moderate-intensity exercise: 710 calories consumed
After intermittent high-intensity-exercise: 621 calories consumed
After intermittent very-high-intensity exercise: 594 calories consumed
And the most interesting finding? The men said they ate less the day after they performed the very-high-intensity exercise when compared to the days after their other workout sessions. This suggests that the appetite suppression experienced after the very-high-intensity workouts extends well beyond the hours immediately following the exercise and that it may even reduce your appetite the following day too.
More Research Needed
Even though this study showed impressive results--participants significantly reduced their calorie intake after the high-intensity and very-high-intensity exercises--it doesn't show one way or the other if this will produce weight loss for the long term. The size of this study was also quite small--only 17 participants. What was unique about this study was that it was the first of its kind to study overweight participants rather than just people with a normal BMI. Scientists say that more studies need to be performed to assess the long-term implications of this type of weight-loss intervention.
Kari Hartel, RD, LD is a Registered, Licensed Dietitian and freelance writer based out of St. Louis, MO. Kari is passionate about nutrition education and the prevention of chronic disease through a healthy diet and active lifestyle. Kari holds a Bachelor of Science in Dietetics from Southeast Missouri State University and is committed to helping people lead healthy lives. She completed a yearlong dietetic internship at OSF St. Francis Medical Center in Peoria, IL, where she worked with a multitude of clients and patients with complicated diagnoses. She planned, marketed, and implemented nutrition education programs and cooking demonstrations for the general public as well as for special populations, including patients with cancer, heart disease, diabetes, Alzheimer's disease, obesity, and school-aged children. Contact Kari at KariHartelRD@gmail.com.