It’s tough to focus on building up your body when your mind is racing. And a new study in the European Journal of Applied Physiology might have clue on why this is.

For the study, researchers asked volunteers to perform an isometric shoulder exercise while doing mental arithmetic until they felt fatigued. The findings showed that when calculating the math, subjects tended to reach fatigue and lost strength faster than when they only concentrated on the exercise. Obviously, nobody’s asking you to do Sudoku puzzles while doing your push-ups. But if your brain is stressed out, it probably won’t be able to focus much on your muscles which could affect your fitness goals.

So what’s the solution? Instead of worrying about what’s on your to-do list, follow these tips to help focus all your mental energy into your workout for faster gains:
Add variety to your workouts
The reason you should switch things up is so you don’t get bored with your regular workout routine. The reason why is that the mind has a tendency to wander once the movements become easier for your brain to figure out. New movements challenge your body, stimulating new muscle growth and strength. An simple trick is just to go another direction, like trading in a front lunge for a side lunge, or replacing sit-ups with dumbbell chops.

Work for time, not reps

If there’s one thing not to worry about to your list is counting the number of reps. Instead, go all-out for a super-short period of time like 30 seconds. Once you can bang out an exercise for 30 seconds straight without breaking a sweat, just up the weights or switch to a more advanced variation of the move to make sure you don’t sacrifice results. If maximum strength and power is your goal, then count your reps once for 30 seconds. Increase the load if you get more than 6 reps.

Find a workout partner

A good workout partner won’t let you slack off as they’ll help push you past your comfort zone, meaning you’ll always get a killer workout. And if you can’t find a workout buddy, consider joining a fitness class. The more people train together, the more energy, sweat, and encouragement you’ll benefit from.