Exercise for Weight Loss? Maybe Not
While exercise is essential to maintain health, our family practice doctors at Cohen Medical Associates in Delray Beach regret to inform you that there’s one thing it probably won’t help you do: lose weight.
Every year, one of the most popular New Year’s resolutions is to lose weight. Sound familiar? If so, you can do it through a proper diet, but studies show exercise may not help you in your quest.
The one exception is athletes, who engage in frequent, high-intensity workouts and are then able to pack away several plates worth of food without gaining weight. But for the average person, asking them to find the time to exercise at that level for hours on end is unrealistic.
What exercise is good for
By no means are we suggesting you skip regular exercise, whether you’re overweight or not. Here’s just a partial list of the types of disorders that can be alleviated or prevented by regular exercise:
- heart disease
- back pain
- Parkinson’s disease
- multiple sclerosis
- chronic obstructive pulmonary disease (COPD)
- anxiety and depression
- peripheral vascular disease
- at least eight different types of cancer.
In addition, in those who have had transient ischemic attacks, or mini-strokes, exercise has been shown to improve blood flow to the brain and diminish the risk of a full-blown stroke. It can also guard against gestational diabetes and postpartum depression in women as well as falls among the elderly.
But unfortunately, weight control is not one of its benefits.
Why exercise won’t help with weight loss
The numbers don’t add up
It’s primarily a matter of metabolism; that is, how much energy your body uses throughout the day.
As obesity researcher Alexxai Kravitz explains, the three main components of energy expenditure are:
1) the basal metabolic rate, or the energy used for its basic functions when you are at rest;
2) the energy used to break down food (thermogenesis); and,
3) the energy used in physical activity.
The basal metabolic rate accounts for between 60 and 80 percent of the calories the average person burns. Digesting food uses up another 10 percent, which leaves only 10 to 30 percent to expend in physical activity, which includes standing, walking, fidgeting . . . all the movement we do during the day, including formal exercise.
“The average person—professional athletes excluded—burns five percent to 15 percent of their daily calories through exercise,” Kravitz told CNN. “It’s not nothing, but it’s not nearly equal to food intake, which accounts for 100 percent of the energy intake of the body.”
Kravitz is an investigator at the the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at the National Institutes of Health (NIH).
Exercise makes you think you can eat more
It turns out that, in general, we vastly overestimate the amount of calories we burn up through exercise. Harvard Medical School estimated the amount of calories expended in various gym activities for 30 minutes.
For example, a 155-pound person would burn 112 calories lifting weights, 205 calories in low-impact aerobics, 260 calories in high-impact aerobics, and 391calories while vigorously riding a stationary bicycle.
One soda or a piece of cake or even a single slice of pizza afterward will undo all that work. In addition, you’re trying to lose weight, not maintain it. That means, you not only can’t increase your food intake after a workout, but instead must keep your intake the same and exercise enough to burn off 3,500 calories in order to lose a single pound.
Or, as Marc Reitman, chief of the diabetes, endocrinology and obesity branch of the NIDDK told The Washington Post, “To exercise your way out of overeating is impossible.”
Michael Joyner, a Mayo Clinic researcher, agrees.
“It’s pretty easy to get people to eat 1,000 calories less per day, but to get them to do 1,000 calories per day of exercise—walking 10 miles—is daunting at many levels, including time and motivation,” he told The Post.
Exercise stimulates your appetite
Besides, any parent who has ever told a kid to “go outside and work up an appetite” instinctively knows that exercise increases appetite.
So not only must you find the time to add a large amount of exercise to your day, you also have to fight off the normal hunger pangs that naturally occur as a result, and resist the urge to take in more calories than usual afterward.
What will work
Again, let us emphasize that exercise is good for you in myriad ways. You must exercise to stay healthy. We recommend any kind of regular, vigorous movement that adds up to 150 minutes (2 ½ hours) per week.
But for sustained, healthy weight loss, we advise a gradual loss of one to two pounds a week. This can be achieved through a sensible diet that includes eating more fruits and vegetables, seafood, poultry, whole grains, beans and nuts, and low-fat or nonfat dairy, and less full-fat dairy products, fatty meats, sugar-sweetened drinks, and sweets.
We will be happy to help design a weight-loss approach that works for you.