Let’s be honest: Who hasn’t made a post-workout beeline through the front door straight to the fridge? A hard physical effort not only deserves a snack, but needs one. Fueling up after an intense training session plays an important role in repairing and rebuilding the muscles that you’ve just broken down through exercise (read more about how much protein to consume to reach fitness goals here). But is exercise always followed by intense hunger, or is it just an excuse to enjoy the activity we love most: eating?
According to a new study published in the American College of Sport Medicine’s monthly journal Medicine & Science in Sports & Exercise, British researchers discovered that working out is an effective way to make you feel less hungry and even encourage you to take in fewer calories. What’s even more surprising is the types of exercise that may work best for appetite control.
“We’ve found that vigorous exercise suppresses appetite while people are exercising and for a short while afterward, about 30 to 60 minutes,” says David Stensel, Ph.D., associate dean of the School of Sport, Exercise and Health Sciences at Loughborough University, and prominent researcher in exercise metabolism. That means that the hardest workouts you do—such as boot camp classes and never-ending hill sprints—may be doubly good for weight loss. You burn a ton of calories while working out and may be less inclined to binge after.
The benefits don’t end when your urge to eat comes back an hour or so later. “When people’s hunger returns, it is normally not any higher than that of those who are just resting,” explains Stensel. In other words, you won’t feel ravenous and ready to inhale an entire pizza in maybe eight bites.
“In the short term, for the average person, it does not appear to be true that exercise makes people hungrier,” Stensel says. “In the longer term—after repeated days or weeks of exercise—people’s hunger and food intake probably does increase, but in most cases this is not sufficient to match the energy expended during exercise.” In layman’s terms, even if you work out regularly, which reduces the appetite-suppressing effects of exercise over time, you probably still won’t be inclined to go hog-wild at a buffet after a workout.
Part of the reason for this self-control may be pride in your work. Feeling a sense of accomplishment from your fitness routine might override thoughts of food. It’s also biological. Stensel’s research measured the amount of ghrelin (an appetite hormone) in the blood after exercise and found that the dial hadn’t moved much from before the workout. However, when the same people ate a restricted diet (eliminating from their meals the same amount of calories they had burned via exercise) ghrelin increased, as did their feelings of hunger. In fact, the test subjects felt so starved when dieting that they ate a third more at the end of the study, taking in 900+ calories after a dieting compared to only 600+ calories after exercising.
The bottom line: Exercise may be a better way to encourage eating less rather than focusing on diet alone. For the best weight-loss results, focus on high-intensity exercise, making sure you reach around 70 percent or higher of maximum aerobic capacity. That includes running, swimming, jumping rope, cycling, or doing any form of cardio, such as intervals, or simply working at a hard intensity. The longer your workout, the longer the appetite suppression lasts, Stensel says. Low-intensity workouts such as walking don’t appear to suppress hunger though they may distract a person from food (if you’re outside in the park, you’re not in your kitchen, right?), thereby, educing caloric intake. Weightlifting also seems to curb craving, at least while people are exercising, but the effects do not seem to be as strong as high intensity cardio, according to Stensel’s work.