Don’t get us wrong—we’re all about bodyweight exercises. And quick, high-intensity routines like the scientific 7-minute workout (plus the research that inspired it) prove you can get in a great workout with very little time and equipment.

But one issue with relying on body weight as resistance is that it can get a little tricky to work the muscles of your back body—you know, your upper and lower back, glutes, and hamstrings.

“It’s easier to find bodyweight exercises that include squatting and pushing than pulling and hinging,” says Noam Tamir, certified personal trainer and owner of TS Fitness. “These exercises are great; however, they mainly strengthen areas that are already dominant and promote short, tight muscles in the front of the body, leading to poor posture, possible injury, and aesthetic imbalances.” (That’s no bueno.)

Source: A Scientific 7-Minute Workout for Muscles You Forget About | Greatist