The expert: Greg Justice, an exercise physiologist at AYC Health & Fitness in Kansas City and author of Mind Your Own Fitness
The answer: It can be fine if it motivates you to get to the gym in the first place (always a good thing). That said, Justice says there are three main reasons why it can also be potentially harmful.
The first reason: You can strain your neck. "When you're on the treadmill, you really need to face forward with your head, your heart, and your hips all lined up," says Justice. But if you're looking down at the screen -- or even if you're looking all the way up if your treadmill doesn't have its own TV and you're watching one on the wall -- you aren't looking straight ahead. "You really heighten your chance for injury in that position," he says.
Another reason watching TV on the treadmill can be a no-no is that you may not burn as many calories. Justice says he sees lots of people holding the sides of the treadmill while they're watching TV -- which can hold you back in general. "While it's OK to hold the handles for a little bit of time if there's a safety issue with balance, holding them for too long means that your full weight isn't supported -- and, thus, you're not burning as many calories," he says.
And finally, there's the repetition factor. Getting into the habit of running while watching Friends can get you into the routine of doing the same thing over and over again -- same speed, same incline -- without switching up your workout. "TV can distract you from mixing things up and shocking the body with speed and incline intervals, which I always recommend to get the most efficient workout in," says Justice.
If you're able to watch TV without craning your neck, holding on to the sides of the treadmill, or skimping on intervals, then you're probably OK running while watching. But otherwise, you're better off turning off the tube. Have trouble working out without watching your shows? Try listening to music, instead -- we recommend this 45-Minute SoulCycle playlist.
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