When people are asked why they run, an overwhelming majority cite the desire to lose weight (and presumably get healthier in other ways as well). But is running really the best way to shed pounds?
“The simple answer is ‘yes, it is a good exercise,’” says Glenn Gaesser, a professor of exercise science at Arizona State University. “Running is as good as anything and probably better than a lot of others.”
On a very simple level, it’s just a matter of calories burned versus calories consumed. And at approximately 100 calories per mile, depending on your size and the terrain, running provides a fairly good bang for your buck: Run faster, cover more miles, burn more calories.
Of course, it can get a lot more complicated than that. Theoretically, losing one pound is roughly equivalent to a 3,500-calorie deficit. Theoretically, that makes the equation very straightforward—but if you’ve found that not to be the case, you’re not the only one.
“You run 35 miles, you should lose a pound,” says Gaesser, “but it never works out that way.”
RELATED: How Many Calories Does Running Burn?
The reason it doesn’t work out is multifold. People tend to overestimate their effort and eat more calories than they actually burned. (That’s not only true if they actually work out, but is also true if they just see people working out. One study, said Paul Williams, a PhD at the Berkeley National Laboratory who has focused on runners and walkers, found that people who watched promotional exercise videos consumed more calories after seeing the vigorous activity on screen, despite not having done anything themselves.)
The other problem is that your body automatically compensates for how much you exercise. Even in a metabolic chamber, which is a closed chamber used as a scientific research tool to measure calories and energy expenditure, there are still compensatory changes in a person’s metabolism after exercise, says Gaesser. What that means is that even when there should be no outside influences, studies have still found that a person’s resting metabolic rate goes down when they’re on an exercise program. Basically, your body finds a way to conserve energy.
Other studies—using motion sensors—have also found that after exercise, especially harder exercise, it’s common for people to become less active throughout the rest of the day. (Imagine yourself lounging on the couch all day after a tough long run.) And there are suspected hormonal changes that happen as well, affecting how you burn fuel, says Gaesser.
That’s partially why, after a certain amount of time running long, slow miles, many people experience a plateau. At that point, a good idea might be to try something else, such as interval training. (Or, get younger. Simply maintaining your mileage as you age—instead of increasing volume or intensity—can still result in weight gain because of metabolic changes that come with years. “If that’s not depressing, I don’t know what is,” says Gaesser.)
“Variety is the spice of life,” says Edward Lakowski, the co-director of Mayo Clinic Sports Medicine.
While running isn’t a bad way to lose weight, just running might not burn off as many pounds as you’re hoping. Weight training can also have a benefit, he says, since muscle does burn additional calories—though people tend to overestimate the amount they truly worked in the gym.
RELATED: Carbohydrate Cycling for Weight Loss
A number of studies have shown that running burns more calories than walking for the same mileage—the break point between walking and running, in case you were wondering, is about four to five miles per hour. In that same vein, high-intensity exercise—be it running fast intervals or something more along the lines of a bootcamp-style circuit—has been shown to have a number of health benefits. There are also some studies that suggest the higher the intensity, the more fat you burn, particularly because very high intensity exercise can have an after-burn effect—burning another 10-15 percent of the calories you did in the workout for a few hours after you’ve finished.
But, warns Gaesser, that only comes from doing at least an hour at 75-80 percent of your VO2 max—the maximum amount of oxygen you can use—which is harder than most people are willing to go.
Plus, if you go too hard or do too much too soon, you might find yourself hurt or burned out—and sitting on the couch won’t burn many calories at all. To that end, cycling or swimming or rowing might be more productive if you’re arthritic or have biomechanical issues when it comes to running. This can make figuring out exactly how to burn the most calories a little tricky.
For example: In an average hour of running at a moderate pace (7-1/2 miles), I burn about 750 calories. An hour of cycling at the same effort (or heart rate) would burn about 450 calories for me. That makes it seem clear cut; running is the way to go. But there’s slightly more to the math. I am only capable of running about five to six hours per week before I start to get avoidable aches and injuries. If scheduling weren’t an issue, I could easily bike 10 to 15 hours each week before having a similar body breakdown. That means the actual equation is some kind of calculation maximizing calories burned as a product of running and cycling, with respect to time and injury potential.
In terms of burning calories, you need to use a lot of big muscle groups—except for one big outlier: swimming. Because of temperature differences in the water and body regulation, swimming tends to be the worst for weight loss, says Gaesser. You lose a lot of heat, which tends to result in more calorie consumption than you actually burned.
“For most people, time is the limiting factor,” says Williams, which is why running is more efficient than walking longer, cycling or swimming. Plus, you don’t need a pool to run or any expensive equipment. It’s also inexpensive, you can do it anywhere and there are also more running races and running clubs than other sports, making it more fun for many people.
“The best exercise is one that people like to do,” says Laskowski. Generally, only one-third of people actually comply with medication instructions and prescriptive exercises, so the more people actually do what they know they should, the better. “The easier it is, the more you’re going to do it.”