Exercise & Loss Of Appetite

Loss of appetite can follow a vigorous workout, and can be a sign that you're training too much. Keeping your workouts under 60 minutes per session and getting plenty of sleep at night are just two ways to reduce the odds of overdoing it at the gym. The primary reason you may experience a loss in appetite following a workout has to do with your body's hormones, according to a 2008 study at Loughborough University in the UK.

Key Hormones

The UK study compared how exercise affects appetite in men. The focus of the study was on two important hormones involved in provoking appetite: ghrelin and peptide YY. Ghrelin is a hormone that stimulates hunger while peptide YY suppresses it. The study found that aerobic and anaerobic exercise, such as weight training, both stimulated an increase in the peptide YY hormone. This is the primary reason healthy people have a feeling of fullness post-workout.

Types of Exercise

The same UK study also compared whether resistance training or aerobic training was better at suppressing appetite following a workout. The results showed that both types of exercise increased levels of peptide YY, but aerobic exercise actually decreased levels of ghrelin while resistance training did not. This makes aerobic training more effective for suppressing appetite, so it could make it a more beneficial choice in terms of weight loss. The study compared 60 minutes of aerobic exercises to 90 minutes of resistance training.

Dangers

In extreme cases, a loss of appetite caused by exercise can be harmful. The American Council on Exercise lists "loss of appetite" as one of the top indicators of overtraining your body. The cause is an unhealthy increase in the release of epinephrine and norepinephrine, which are both appetite suppressant hormones. Monitor your daily calorie intake to make sure it's well within the Department of Health and Human Services recommendations of at least 1,000 calories per day for women and 1,200 calories for men. Also, listen to your body for signs of overtraining, including chronic muscle soreness, frequent illness and restless sleep.

Exercise Recommendations

Follow the Centers for Disease Control and Prevention recommendations to exercise at the right intensity and take advantage of the positive effects of exercise rather than the potential negative aspects. The CDC recommends you perform at least 150 minutes of moderately intense aerobic exercise each week. As you become more physically fit, you can increase this figure to five hours per week total, or the equivalent of five 60-minute workouts. This workout regimen will allow you to get the appetite suppressant benefits that aerobic exercise offers without overtraining your body.