Is Your Phone Destroying Your Workout?

Can your smartphone actually reduce your physical performance? Get-Fit Guy explains the results of a new study that will make you rethink your nighttime routine.

Ben Greenfield,
January 23, 2015

It's a fact that your smartphone can help you get fit. You can use it to download workouts, exercise videos, tracking apps, or music to keep you motivated.

But there is one way that your phone could actually be destroying your workout, especially if you’re a morning exerciser.

A recent study entitled “The Effects of Evening Bright Light Exposure on Subsequent Morning Exercise Performance.” investigated the effects of evening bright light on people’s circadian rhythm and their morning exercise performance, along with their core temperature during that morning workout.

Researchers took two groups of men and subjected one group to a polychromatic bright light (at a light setting almost identical to that of the average smartphone) at 10pm for 30 minutes. The other group had no light. The next morning, the test subjects rode a hard 10 kilometer time-trial on a bike in hot conditions (in a room kept at 35°C and 60% humidity).

The study found that not only did the subjects who saw the light at night have a more difficult time regulating their core body temperature, but they also found that their nightly temperature took nearly 2 extra hours to dip into the range that it should ideally be dropping to during sleep, which can affect the body’s ability to recover and to repair muscle.

While the good news is that the bright light didn't actually make them slower on their bikes the next morning (although it would be interesting to see the effects on, say, a hot Ironman triathlon versus a 30-minute bike ride), the bad news is that if you’re looking at your phone every night before bed, you will probably be affecting your recovery and sleep quality long term!

So what’s my strategy?

I keep a paper book next to my bed (yes, I know that’s so old-school). If I want to read before bed, I use as dim a light as possible (technically one of those red light producing heat lamps which cost about $10). By avoiding the smartphone screen light at night, I get better quality sleep and can enhance my workout recovery by allowing my body’s core temperature to decrease properly at night.

Do you look at your phone at night? Have you ever tried not doing that? Has it changed your performance or recovery? Head over to Facebook.com/GetFitGuy and let us know your experiences!

Man with smartphone image courtesy of Shutterstock.