Raising your hands overhead seems easy enough.

But many men lack the shoulder mobility to do it properly. As their arms go up, their elbows bend, their backs arch, or their shoulders roll forward, says Men’s Health Fitness Director B.J. Gaddour.

Related: The Anarchy Workout From Men’s Health: 2 Dumbbells, 30 Minutes, Hundreds Of Calories GONE! 

And that spells trouble during exercises like the pullup, military press, the overhead squat, or the push press.

Since you can’t get full range of motion with your tight shoulders, your back has to take the brunt of the load, Gaddour explains. Over time, this can hurt your strength progress and lead to serious back problems.

However, the two-to-five minute mobilization shown in the video above can make your shoulders more mobile. Do it between sets of exercises, or before or after your workout, recommends Gaddour. It’ll increase your gains during all overhead exercises, protect your back, and keep your shoulders healthy for the long run.