|Can You Be Fit and Fat?|
|By the Editors of Runner's World||Apr 26, 2011, 2:26 PM|
Many of us would describe the ideal runner's body as lean, lanky, lithe. But then someone who is none of those things blows past us in a 5-K, leaving us questioning what "fit" really looks like. Some doctors say people who are overweight (body-mass index, or BMI, of 25 to 29.9) or obese (BMI above 30) will face health issues, regardless of how often--or fast--they run. But some studies show that heavy people who exercise can be cardiovascularly healthy and may live longer than their sedentary but skinny peers.
We asked two experts to, ahem, weigh in. Glenn Gaesser, Ph.D., director of the Healthy Lifestyles Research Center at Arizona State University, says you can be fit and fat. Amy Weinstein, M.D., M.P.H., an assistant professor at Harvard Medical School who studies the impact of obesity and exercise on disease, disagrees. Here's why.
Is it possible to be overweight and healthy?
Virtually every weight-related health problem can be greatly improved or cured with a moderate level of exercise, even if you're overweight. The amount of exercise necessary to achieve a fitness level that greatly reduces disease and mortality risk is the equivalent of brisk walking for 30 minutes a day, five days a week, or running 20 to 30 minutes a day, three days a week.
Based on research I've seen and studies I've performed, it appears that physical activity cannot completely reverse the ill effects of carrying excess weight on diabetes and cardiovascular disease. The reason for this is unclear. There may be hormones and proteins that regulate weight and affect chronic diseases, which physical activity cannot reverse.
But can a butterball really outrun a lean machine?
It's possible for a heavier runner to be faster than a thinner runner if the heavier runner has the necessary ingredients for better endurance: higher VO2 max, higher lactate threshold, and better running economy. Genes play a huge role as well, as does experience.
Well, sure, it's not impossible. But a person who is overweight would be faster if he lost weight. A loss of about two pounds will theoretically increase speed by about a meter per minute of running. So if a runner runs a 5-K in 20 minutes, a two-pound weight loss would make him five seconds faster overall.
Do heavy runners get injured at the same rate as thin runners?
Being overweight increases your risk of arthritis. Research shows that obese people have almost three times the risk of arthritis in the knees. So it would make sense that heavy runners are at a higher risk of injuring their joints.
Should runners disregard age-related weight gain?
To control your weight as your metabolism slows down, you probably have to double your exercise. After age 40, you'd need to run about two more miles per week, each year, in order to maintain your weight. So if you are running 25 miles a week at age 40, you'd have to do 27 miles at 41, 29 miles a week at 42, and so on. That might be more than most people are willing to do. That's why I promote physical activity for health and not for losing weight, because it takes a lot. If your weight is creeping up but your cholesterol and blood pressure stay in the healthy range, I wouldn't worry about it.
As your weight goes up, so does your risk of all sorts of chronic diseases. So I tell patients whose weight may have been steadily inching up to not concentrate on weight loss. Rather, let's first stop the weight gain. Even if it's just one pound a year, that's 20 pounds in 20 years, which is significant.
Is consuming fewer calories the best way to lose weight?
If someone wants to lose weight, restricting calories will do it, but he'd be healthier if he'd exercise as well. In a large study published in 2010, researchers looked at a group of people who only dieted, and another group who dieted and exercised. Both groups maintained exactly the same calorie deficit each day, and therefore lost the same amount of weight. But the diet-plus-exercise group experienced much better changes in certain health markers. Also, resistance exercise can build muscle, and more muscle can help you burn more calories even when you're at rest. And exercise is especially good at helping you keep the weight off once you lose it. So if there's one message here for people who are adamant about trying to lose weight, it's that you may get pounds off with dieting but to keep them off you're going to have to exercise. You'll be healthier for it, too.
Do the benefits of exercise matter more than losing weight?
Physical activity can lower your risk of cardiovascular disease, regardless of your weight. Whether you're talking about boosting good HDL cholesterol, lowering bad LDL cholesterol, reducing blood pressure, and so forth--all these can be improved with exercise, even if you don't lose weight. And this results in a lower cardiovascular-disease risk. Physical activity seems to have a profound effect on overall mortality risk as well--again, regardless of your weight.
Exercise can improve your health, but you can list more than 50 medical conditions--from diabetes to arthritis to acid reflux to sleep apnea to certain cancers--that result from complications from carrying excess weight. Even losing five or 10 pounds will lower your risk of developing these issues and improve your health.
So is it more important to exercise than to lose weight?
It's been shown that about twice as many people achieve their exercise goals compared with their weight-loss goals. Weight loss may happen with exercise, but it may not. Over the past 30 years, millions of Americans have attempted to lose weight. Yet we're heavier now than ever. Something's not working. So instead of emphasizing losing weight, let's emphasize getting fit. Never mind losing 30 pounds, how about walking for 30 minutes?
I'd like to see exercise--along with a healthy diet--promoted as a way to solve the obesity epidemic. I run a weight-management clinic, and I've been trying to get patients to lose weight. I've found it's actually not that hard to change people's behavior--their diet and physical activity, in this case. Americans simply need to exercise more and lose weight.
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