There’s a widely-held view that the formula for weight loss is simple – just eat less and exercise more. The reality is that such strategies generally fail to deliver significant weight loss benefits. The newest science suggests that exercise alone will not make you thin, although it may help you stay thin, healthy and happy.
I was reminded of the relative ineffectiveness of exercise for weight loss by a recent study with 320 post-menopausal women randomized to one of two groups:
- 1. An exercise group, instructed to engage in moderate-to-vigorous exercise for 45 minutes, 5 days a week.
- 2. A control group, who were not to change their normal activity habits.
Both groups were asked not to change their diets. At the end of the year, women in the exercise group were found to have exercised for an average of 178.5 minutes a week. This equates to 155 hours over the course of the year.
Compared to the control group, these women lost an average of 4 lbs in weight. If we do the math we see that women exercised for about 39 hours for each lb loss in weight! Overall, dietary change appears to be significantly more effective for weight loss.
Why is it that aerobic exercise is not great for weight loss? For one, exercise can make people hungrier. It doesn’t take much in the way of additional intake to undo the limited ‘calorie deficit’ induced by exercise. Secondly, often times after exercise people end up being more sedentary the rest of the day. Third, endurance exercise can increase the levels of hormones, notably cortisol, that may work to stimulate fat storage.
But don’t let this news frustrate you or cause you to resign to becoming sedentary. Instead, maintain reasonable expectations – forget about exercise as “burning calories” or “melting away fat – and do exercise for different reasons: enhanced fitness, sense of achievement, or enjoying nature. I believe there are benefits to exercise that go way beyond any loss of body fat. For me, exercise is not really about weight control, but about being healthy and having fun.
Take your exercise outside – Research shows that exercising outside confers even greater physical and mental benefits compared to the same exercise indoors.
How many of us have taken a long walk in the woods, and felt soothed by the sound of the wind in the trees and the crisp smell of leaves? Or have been moved by the beauty of a snow-capped mountain range? Research tells us that our relationship with nature is a fundamental component of maintaining good health. This “biophilia hypothesis” suggests that there is an innate affiliation of human beings to other living organisms, both flora and fauna, and perhaps even an innate bond with nature more generally.
Take a long walk at your local park rather than plugging away on the treadmill in your fluorescent-lit gym. Take advantage of warmer, sunny days and move your workout into the wilderness. It may take some creativity or extra planning, but the mental and physical benefits will be worth the effort. You may even find yourself enjoying your workout more than usual!
“Forget not that the earth delights to feel your bare feet and the winds long to play with your hair.” – Khali Gibra
1. Friedenreich CM, et al. Adiposity changes after a 1-year aerobic exercise intervention among postmenopausal women: a randomized controlled trial. Int J Obes (Lond). 2011;35:427-435
2. Wu T, et al. Long-term effectiveness of diet-plus-exercise interventions vs diet-only interventions for weight loss: a meta-analysis. Obesity Reviews 2009;10:313-323
3. Shaw K, et al. Exercise for overweight or obesity. Cochrane Database of Systematic Reviews 2006, Issue 4. Art. No.: CD003817.
4.Weighing the Evidence on Exercise, Gretchen Reynolds. New York Times, April 16 2010. This is an interesting New York Times article about exercise.