Does where you run really matter? You might suspect that you're somehow getting a better or harder workout when you head outdoors. But is that actually true? And if so, does that mean you should steer clear of the treadmill?
Unfortunately, the question of treadmill vs. running outside doesn't actually have a one-size-fits-all answer. Here's a look at the factors that are worth considering — the pros and cons of both options — and how to pick the right running location for you.
Treadmill vs. Running Outside: Which One Is Better?
The truth is, one method isn't definitively better than the other. Treadmill running has a reputation for being easier than running outside, but that's not actually the case. A 2019 review published in the journal Sports Medicine found that runners' heart rates and oxygen intake for both are about the same, provided you crank up the incline to 1 percent (which makes up for the lack of air resistance indoors).
Deciding where you'll run is about figuring out what will help you best achieve your goals. And the answer doesn't have to stay static. "I believe people should run wherever is going to give them the best workout that day," says Jason Karp, PhD, founder of Run-Fit and author of Running a Marathon for Dummies. Weighing the ups and downs of both options can help you pick one.
The Pros and Cons of Treadmills
Like all fitness equipment, treadmills have their benefits and their drawbacks. However, for many, they can be a good choice because:
You get instant feedback. All you have to do is check the display for data on your speed, distance, incline and calories burned. (Of course, if you'd rather not see it, you can also cover the screen.) That can make it easier to meet specific benchmarks you might be aiming for.
There's an added comfort factor. You might feel better about running on a treadmill after an injury or illness, since there's no risk of getting stuck halfway through your outdoor run and far away from home, Peek says.
You can be more flexible with your schedule. Prefer to avoid running outside in the dark? Want to squeeze in a workout while your kids are playing happily in the other room? Treadmills can help you make that happen, Peek says.
Still, these machines aren't perfect. Some people dislike treadmills because:
They can make running feel harder. Runners tend to rate treadmill workouts as more difficult and less satisfying, according to a 2004 study from Psychology of Sport and Exercise. And one 2012 study published in Gait and Posture found that when people went from running outside to running on a treadmill, their pace was slower — even though they felt like they were running at the same speed.
You might be more tempted to cut your workout short. The reason why is pretty obvious: "People get bored on the treadmill," Karp says.
When to Run on a Treadmill
Hopping on the treadmill can help you fit in a run regardless of the weather or your schedule. Same goes if you're looking for a highly controlled workout — like running at a certain speed or sticking with a specific incline — or you want to run without going far from home.
You can use a treadmill to train for an outdoor race too, Karp says. "People should just do similar workouts that they would do outside and incorporate changes in grade, just like they'd get outdoors," he says.
If the temperature for your race will be a lot different than what you're used to, consider simulating that during your runs. Running a race when you know the temps will be hot? Try cranking up the thermostat inside to help you get used to the extra warmth, Peek says.
When the treadmill feels less entertaining than running outside, think about ways to stay motivated and avoid stepping off early. For example, only let yourself watch your favorite show or listen to a new binge-worthy podcast when you run.
The Pros and Cons of Running Outside
Running outside has some obvious benefits, along with a few less-expected ones. For instance:
You're less likely to get bored. There's always something new to look at when you're running outside, especially if you switch up your route.
You'll reap the benefits of nature. Exercising outdoors isn't just more mentally stimulating, it's been found to boost mood and self-esteem, according to a 2010 review from Environmental Science and Technology. If it's sunny, you'll also get a welcome dose of vitamin D, Peek says.
You'll get better at pacing yourself. That can be especially beneficial for racing. "When running on the treadmill, we tend to set the incline and speed and just go," Peek says.
But it's not all good news. There are some downsides to outdoor running, too, like:
You have to deal with the elements. Under perfect conditions, running can be downright invigorating. But slogging it out in the heat or rain or trudging against icy winds? Not so much.
You have less control. Unless you've run the exact same route a thousand times, it can be tough to maintain your pace when the terrain or incline changes without warning.
You're farther away from home. There's always the possibility of getting lost or injured. (Which is why you always run with your phone and tell a friend or family member where you're going, right?)
When to Run Outside
Running outside isn't inherently better than running indoors on a treadmill, so you shouldn't feel pressured to do it just because you think it'll give you more of a challenge. But both Karp and Peek agree that if running outside feels more enjoyable and the treadmill tends to make you bored or antsy, heading outdoors is likely the better choice.
It's also worth getting outside at least some of the time when you're training for an outdoor race. While you can simulate different hills and terrain by changing the incline on the treadmill, running outdoors will help you learn how to pace yourself instead of relying on the 'mill display.
Weight Loss and Calories Burned With Each
You can get a great workout by running outside or running on a treadmill. You'll burn more calories outdoors than on a totally flat treadmill, but as mentioned above, research suggests that you can adjust for the difference by setting the incline to 1 percent. Set it higher or vary the gradient up and down, and you'll come close to mimicking a hillier outdoor run.
OK, but how many calories will you actually burn? The specific number you torch will depend on factors like your individual metabolism and weight. (That's true for outdoor or indoor running, though it's important to remember that the calories on your treadmill display are just a ballpark estimate.) In general, though, the amount depends on how fast you're running. In 30 minutes, a 150-pound person will burn around:
- 443 calories at 8 mph
- 341 calories at 6 mph
- 273 calories at 5 mph
With numbers like that, running at any speed — indoors or out — can add up to pounds lost over time when combined with a healthy, reduced-calorie diet. At the end of the day, it's ultimately about choosing a running routine that you'll do regularly.
"The most important aspect of training is consistency," Peek says. "If using a treadmill means you'll be more consistent, that's the way to go. If running outside means you'll be more consistent, lace up and get out the door."
Perceived vs. Real Benefits
A lot of the perks of running outside have to do with how it makes you feel. Indeed, the same Psychology of Sport and Exercise study found that outdoor runners have a greater sense of positive engagement, revitalization and tranquility compared to those who use a treadmill. And that mood boost could give you more energy overall — like your run is barely any work at all.
That could add up to a more productive workout. "When running outside, you see things and are stimulated. Stimulation goes a long way toward creating a better workout and a better experience," Karp says. As a result, he says, "you're probably more likely to push longer or harder."