The Complex Relationship Between Exercise and Hunger

Exercise is widely known to have numerous benefits for the body, from building muscle and burning calories to strengthening the heart. However, what many people may not realize is that exercise can also significantly impact appetite and hunger levels, especially when it comes to intense or prolonged physical activity.

How Exercise Suppresses Appetite (At Least Temporarily)

During exercise, it's common to experience a suppression of hunger. This occurs in part because blood flow is diverted away from the stomach to supply the working muscles with oxygen and nutrients. As sports dietitian Jen Sommer-Dirks explains, "That's why it's hard to digest food when working out."

Additionally, exercise triggers changes in hormones that regulate hunger and appetite. Studies have shown that activities like running and strength training can lower levels of ghrelin, a hormone that stimulates appetite, while increasing peptide YY, which suppresses appetite. The intensity and duration of exercise also play a role, with higher intensity and longer workouts having a more pronounced effect.

Another factor is body temperature - as nutritionist Heidi Skolnik points out, "When you work out intensely and long, you get hot. When you're really hot, you're not hungry." This appetite suppression often lingers for some time after the workout, until the body has had a chance to cool down.

Refueling Properly Is Key for Weight Loss and Performance Goals

While a temporary reduction in hunger may seem like a good thing for those looking to lose weight, it's crucial not to skip post-workout nutrition. Sommer-Dirks emphasizes, "If you're trying to build muscle or improve your performance, getting nutrients after a tough session is key for making progress. You need protein for muscle recovery and repair, and carbohydrates to replenish glycogen stores."

Failing to eat after a hard workout can leave you feeling sluggish and underperforming in your next session. If your appetite is suppressed, Sommer-Dirks suggests trying liquid options like a protein shake blended with milk and fruit, which may be easier to digest.

Don't Rely on Exercise Alone to Control Appetite

It's important not to view exercise solely as a tool for suppressing appetite in order to eat fewer calories and lose weight faster. As Skolnik cautions, "My experience with athletes is they have a suppression of hunger, but then later they're starving." This can lead to overeating and making less healthy food choices when hunger does return with a vengeance.

Furthermore, exercise selection should be based on a well-rounded approach that includes both cardio and strength training for their various benefits, rather than just appetite suppression. Sommer-Dirks advises, "Within that, choose enjoyable activities so you're more likely to stick with them long-term."

The Bottom Line

While exercise can temporarily curb hunger, it's essential to listen to your body's needs and fuel properly to support your fitness goals, whether that's weight loss, muscle gain, or improved performance. Incorporate a balanced mix of cardio and strength training, eat a nutritious post-workout meal or snack within 45 minutes of finishing, and focus on consistent, enjoyable physical activity for long-term success.