Another way a treadmill can make running more accessible? Say you’re training for a race in a different location—maybe the Boston Marathon, with its famous hills—but you live in the pancake-flat Plains. With a treadmill, you’d be able to use incline to practice the ascents and prepare your body for them (without having to, you know, hop a plane to Massachusetts.) In fact, treadmills like the NordicTrack, with its iFit programming, have certain races pre-programmed; if yours doesn’t, the RunBetter App guides you through when to adjust your incline manually for more than 50 different courses.
But you’re not imagining it: Treadmill running can definitely feel harder than when you’re outside.
In a systematic review and meta-analysis of 34 studies published in the journal Sports Medicine, Dr. Willy and his colleagues found no major physiological differences between running on the treadmill and what researchers call overground running at most speeds. (That holds true for motorized treadmills. Those you power on your own—like the Woodway Curve or the TrueForm Trainer—are more demanding, he says.)
But the data do show the rate of perceived exertion—how much effort it feels like you’re putting in to keep up the pace—is higher on the treadmill.
Why? For one thing, you’re lacking optical flow, or the experience of seeing your surroundings change as you speed by, he says. And, you won’t feel the air rushing past you, either. Because both of these provide information to your brain about how fast you’re moving, any pace feels like a bit more of a slog without them.
The fact that there’s no scenery to distract you also plays a role. That’s why many people turn to TV, podcasts, or even reading to make the miles pass more quickly, Brian Cleven, MS, ATC, an ACSM-certified clinical exercise physiologist at Bellin Health in Marinette, Wisconsin, tells SELF. (Dr. Willy, for instance, can read journal articles during some of his easier treadmill runs.)
You might also find having the pace or time constantly in your face makes it all drag even more. After all, when you’re running outside, you can only steal occasional glances at your watch. In that case, Goodman recommends covering up the display with a towel. Go by heart rate or how hard you feel like you’re working rather than by minutes per mile or miles per hour, and use the buttons on the arms or side of the machine to control pace and incline.
Playing with the incline or other settings can help, but you don’t need to in order to get a “good” workout.
You might have heard that you need to bump up the incline to 1% to create similar conditions to outdoor running. But that’s based on old data, Dr. Willy says. The only time you might consider doing that is if you’re super speedy, going faster than that 7-minute mile (about 8.6 miles per hour, if that’s how your screen displays it). At that point, treadmill running does use a little less energy than running on the ground, and the slight incline offsets that shift, he says.