Sometimes they are the key to a stronger, fitter butt and legs, according to recent research published in the Journal of Strength and Conditioning Research.

Experts believe that shallow squats help increase power by letting you use heavier weights, says certified strength and conditioning specialist Brad Schoenfeld, assistant editor-in-chief of the Strength and Conditioning Journal. When you keep your butt above your knees during a squat, you don’t have to deal with the “sticking point,” where you need some extra oomph to raise up.

To reap partial squats’ full benefits, you also need to squat deep at least some of the time. “Deep squatting has been shown to have the greatest effect on muscular development,” says Schoenfeld. “Without squatting deep, you will compromise muscle gains.” Full squats train a greater length of your muscle fibres compared to partial squats. In the study, exercisers squatted to a full 90 degrees during half of their sets.

How often you squat is up to you, but once a week is a good baseline, says Schoenfield. If you wanted to follow the study’s protocol, you would do half of your sets as full and half as partial, but research has yet to determine what the optimal combo is.

READ MORE: “I Did 50 Squats Every Day For A Month — Here’s What Happened”

How to Partial Squat

Schoenfeld says that to get the most from the move, you should be using heavier weights than you do during deep squats. How can you tell if you’ve gone heavy enough? Maintaining proper form, you should just be able to eek out your last rep. You can complete partial squats using a barbell or dumbbells on your shoulders, or a single dumbbell, kettlebell, or weight plate at your chest.

Stand tall with your feet shoulder-width apart. Push your hips back, and bend your knees to lower your body until your butt is just above your knees. Pause, then slowly push yourself back to starting position.