• Taking your phone into the gym with you could be sabotaging your workouts, according to Scarlett Johansson’s personal trainer.
  • People end up mindlessly scrolling through social media, making their rest periods much longer than they should be to get the best results.
  • Tracking your rests between sets “can improve your workout exponentially,” say Eric and Ryan Johnson.

On any trip to the gym, certain sights are a given: squirming faces from PT victims, gym bros grunting their way through each bicep curl, and people sitting around on their phones.

Yes, whether you’re taking selfies in the mirror or scrolling through Instagram while waiting for the dude on the leg-press to quit hogging the machine, gym-goers always tend to have their phones on them these days.

But according to two celebrity personal trainers, having your phone on you while you exercise could be sabotaging your workout.

Ryan and Eric Johnson are the brothers behind Homage Fitness, a new line of gyms in private residences across Miami, New York, and D.C. designed to combine top level fitness with hospitality.

The brothers, who are certified strength and conditioning coaches, have over a decade of experience in the fitness industry.

Eric also happen to be Scarlett Johansson’s personal trainer and the brothers have worked with her and other actors on films such as “Captain America: Winter Soldier,” “Ghost in The Shell,” and “Avengers: Infinity War — Part 1.”

Read more: Here’s why Scarlett Johansson’s personal trainers suggest always eating dark chocolate before a workout

Ryan told INSIDER that people should leave their phone in the locker room if they want to make their workouts more efficient. Otherwise, they end up mindlessly scrolling through social media, making their rest periods much longer than they should be.

The only time exception to the rule is if your phone is the only way you can track and measure your rest periods, which he says is essential — but there are watches or clocks you can use for this.

“It’s very easy to get distracted in the gym and let your minute-long rest turn into three or four minutes which in turn is going to make the intensity of your workout go way down,” he said.

“By systematically measuring and tracking your rest time, that creates a much cleaner programme. Knowing that, say, between every set you’ve had a minute and a half rest, it’s really pleasing to the brain.”

The brothers believe being regimented about your rest time can “improve your workout exponentially.”

Taking some rest time between sets in the gym is recommended by fitness experts, but how long yours last depends on your goal.

“If you’re after maximal strength, longer rest intervals will allow you to optimally achieve higher intensities (the amount lifted),” the brothers explained. “With large muscle compound movements that generate high levels of metabolic disturbance like squats, deadlifts, presses, and rows, the optimal strategy will be to take two to five minutes between sets.”

This ensures the muscles have adequate time to regenerate energy before the next set — ideally, you should perform these moves at the beginning of your training session.

“If you are looking to create metabolic stress in order to prioritize fat loss or hypertrophy [the growth of muscles], the strategy should call for shorter rest periods,” the brothers explained. “Isolation types of exercises, like biceps curls, tricep extensions, and leg extensions, are not as metabolically taxing and require less recovery time.

“Therefore, to heighten metabolic stress and cellular swelling (the infamous ‘pump’ where the muscle becomes engorged with blood), it is best to keep rest periods between 15 to 60 seconds.”

They added that you should work on these single joint movements towards the end of your workout when your energy is lower — and to make sure you’re really focusing, leave your phone in your bag.

“The removal of distractions will allow you to be more present and aware during your workout,” the brothers agreed.

“Not only will you become more efficient, your undivided attention will improve the amount of effort you put forth, reduce the chance of injury, and probably have a lot fewer gym enemies.”

Originally published on Business Insider.

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