Friday, December 7, 2012

Suppress Your Appetite With Exercise!

For years, researchers have known that hard exercise suppresses appetite, known as “exercise-induced anorexia” (anorexia= lack of appetite). You may recall this after running sprints or after a killer plyometric training session. Many runners know that they are not very hungry for hours after a race if they ran it at maximal intensity. A recent study showed that those who did aerobic training for 12 weeks had a higher perceived fullness after both fasting and eating compared to those that did resistance training for the same time duration. So, in addition to torching calories during an intense aerobic exercise, your body triggers changes in the hunger hormones which can potentially cause you to eat less afterwards. Just weight lifting and other forms of resistance training didn’t seem to have the same benefit in this study, although resistance training is VERY important for boosting your metabolism (by adding muscle), preventing osteoporosis, and keeping you strong as you age. Another study out of BYU showed that women who walked vigorously on the treadmill for 45 minutes in the morning had less interest in food than on days they didn’t.

My recommendation:  In addition to burning lots of calories, aerobic exercise such as spin, plyometrics classes, and running have the added benefit of decreasing your appetite afterwards. The problem lies in the fact that you may be less hungry than you are normally, but you still probably eat (which is important to replenish glycogen stores in the muscles). Most people have a skewed estimate of how many calories they actually burn during exercise, and may tend to overcompensate and eat more calories after a workout than they actually burned- which is why most of us who exercise are not losing weight. Just know that when an exercise instructor tells a class they are burning "600 calories/hour!" that may not necessarily be for you... especially if you are a small woman (you might only be burning 300). Calorie burn depends on your size, muscle mass, and the effort you put in. If you want the most bang-for-your buck, make sure you incorporate interval training into your workout routine regularly to burn calories, reduce abdominal fat, and get the most benefit out of the appetite-suppression. I recommend investing in a heart-rate monitor (X-mas present request???) to give you a better idea of how hard you are actually working and to give you a better estimate of how many calories YOU are actually burning.

Beneficial effects of 12 weeks of aerobic compared with resistance exercise training on perceived appetite in previously sedentary overweight and obese men. Kym J. Guelfi, Cheyne E. Donges, Rob Duffield

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