Everyone knows that exercise helps to promote weight loss. Most people believe that this is because more calories are burned when you're active as opposed to when you're sitting around the house.
While this is certainly true, it isn't the whole story. Here are three additional ways that exercise fires up weight loss and helps to keep you lean for the long haul.
If you've been keeping up with my previous posts, you're undoubtedly aware that exercise produces an "afterburn" where metabolism remains elevated for several hours once you finish training. Fat burning following exercise is due to a phenomenon called excess post-exercise oxygen consumption (EPOC).
EPOC requires energy to be expended in order to return your body to a stable state. Research has found that EPOC is intensity dependent. What that means is that the harder you train, the more calories you burn following the workout. Thus, while an activity such as walking will have a minimal afterburn, performing high-intensity interval training can result in over 100 additional calories burned over and above what you burned during the exercise session itself.
Lifting weights can have an even greater effect on EPOC. If you keep rest intervals short and really push yourself on each set, EPOC can last for over 38 hours post-exercise! Pretty cool, huh?
Exercise also facilitates weight loss by increasing resting metabolism. An increased metabolism turns your body into a fat-burning machine.
One caveat: Not all exercise will help in this regard. In fact, only strength training has a positive impact on resting metabolism.
Here's why. Strength training builds muscle. Muscle is the most metabolically active tissue in the body. Although it has been proposed that each pound of muscle burns in excess of 50 calories a day, that number now seems to be a bit inflated. Recent research suggests that the actual amount is probably in the range of 30 to 35 daily calories.
That's still not too bad. If accurate, adding a mere five pounds of muscle will allow you to burn an extra 150 calories each and every day. That means you'll burn an additional pound of fat every three weeks or so… even while you're doing nothing more than lounging around the house!
Finally, exercise can have an indirect effect on weight loss by suppressing hunger. Understand that weight management follows a general rule of thumb: calories in vs. calories out determines whether you gain, lose or maintain your weight.
This is consistent with Newton's First Law of Thermodynamics: take in fewer calories than you expend and you'll shed the poundage.
The good news: studies show exercise has a positive effect on levels of satiety.
Strength training, in particular, has been shown to induce a feeling of fullness by reducing levels of a hormone called ghrelin. This ghrelin has been dubbed “the hunger hormone” – and as ghrelin levels rise, so does the urge to eat.
A recent study found that ghrelin levels fell 13-21% after an intense bout of strength training.
Other satiety-related hormones are also favorably regulated by exercising, thereby helping to prevent the temptation to binge.
Brad Schoenfeld is one of America’s leading fitness experts. He’s the best-selling author of Sculpting Her Body Perfect, 28-Day Body Shapeover and his newest book, Women's Home Workout Bible. Schoenfeld is certified as a strength and conditioning specialist by the National Strength and Conditioning Association and as a personal trainer by both the American Council on Exercise and the Aerobics and Fitness Association of America. He’s also been named “master trainer” by the International Association of Fitness Professionals. Check out his website at www.lookgreatnaked.com