“Want to lose weight? Then run, don’t walk,” reported U.S. News & World Report in the April 2013 issue.
To study walking versus running, the Lawrence Berkeley National Laboratory in California conducted a six year National Walkers’ and Runners’ Health Study. When they compared men and women who increased their walking or running, they found that running expended more energy than walking.
But people who choose to run may be different—they may be more physically fit, for example—than people who choose to walk.
A control group helped eliminate variables.
To avoid the pitfalls of lifestyle differences in a comparison of walking with running, Cris Slentz and his colleagues at the Duke University School of Medicine in North Carolina recruited 120 overweight or obese middle-aged men and women. They were then randomly assigned to one of three exercise programs or to a non-exercising control group.
The exercisers worked out on treadmills, cycles, or elliptical trainers at an intensity equal to either walking or jogging. All were told not to change what they ate.
The results are in.
After six months, those who exercised the equivalent of walking 11 miles a week had lost the same amount of weight—about three pounds—as those who exercised the equivalent of jogging 11 miles a week. But it took the “walkers” three hours a week, while the “joggers” needed only two hours.
“It takes longer to burn the same amount of calories when you’re doing moderate-intensity activity like walking instead of running or other vigorous exercise,” explains Slentz.
“Intensity doesn’t have a significant effect on weight loss or fat loss,” he adds. What matters is the total number of calories you burn.
Not surprisingly, a third group, which did the equivalent of jogging 17 miles per week—it took them three hours—lost the most weight: eight pounds over the six months. Of course, they burned the most calories.
But many middle-aged and older people won’t—or can’t—do vigorous exercise.
“If you’re lean and you can go jogging and not hurt yourself, that’s what you should do,” says Slentz. “But it turns out that moderate-intensity exercise is probably pretty darn good for you. And at the end of the day, if people like to walk, they’re more likely to walk than they are to run.”
It’s just that most people don’t do enough. “Instead of 30 minutes a day, five days a week, it would be better to do 45 minutes, seven days a week,” says Slentz.
When it comes to your heart, though, intensity matters.
And changing intensities may make a big difference. Researchers call it high-intensity interval training, or HIT.
“If you want to increase cardiovascular fitness, vigorous exercise is probably the second best, and high-intensity interval training is probably the best,” says Slentz.
“There’s not a ton of research on it yet, and most of the papers are young people getting on a bicycle going 30 seconds all out, busting their gut, trying to do it four or five times, and then taking 30 minutes of slower cycling just to recover from what they did to themselves,” notes Slentz.
“They do it three times a week, so it seems like it’s hardly any exercise because it’s only 30-second bouts times four or five times,” he adds. “But nobody’s going to do that at middle age or older.”
So Slentz is hoping to study what he calls MINT, or modified-intensity interval training.
“We’re going to get 70-to-90 year olds on a bicycle or treadmill, and we’re going to try to get them to do 30 seconds or a minute, if possible, of vigorous exercise, then rest for a few seconds, then work really hard again,” he explains. “We think that’s going to be a very good way to improve their cardiovascular fitness.”
While it’s good for the heart, there’s no good evidence that interval training is better for weight loss than continuous exercise. When it comes to shedding pounds, it’s the calories you burn…and the calories you eat.
“Exercise can cause some modest weight loss,” says Slentz, “but you can lose more by dieting.”
It’s not just a question of losing weight, though. It’s also not gaining weight.
“Don’t assume you’re going to stay thin if you continue to be inactive,” says Slentz. “You’re going to gain weight, and it will probably happen faster than you think.
“If you take enough people and weigh them, and six months later you weigh them again, some won’t have gained weight, but most will have gained some, and a few will have gained a lot. Weight gain happens.”
Do you have experience with weight loss from walking vs. running? Let us know in the comments.
Sources: Med. Sci. Sports Exerc. 45: 706, 2013; Arch. Intern. Med. 164: 31, 2004; Med. Sci. Sports Exerc. 42: 1951, 2010; Int. J. Obes. 32: 684, 2008.
This post was originally published in 2014 and is updated regularly.