If you want to see great results in the gym, build more muscle and get ripped, the squat is a non-negotiable. A heavy barbell squat hammers almost every muscle in your body while stimulating a lot of growth and a massive hormonal response—over time, including squats in your workout will help you gain more size and strength overall. 

Squats are often called “the king of exercises” not only for its physical benefits, but its hormonal advantages as well. Multiple studies have shown that heavy barbell squats help release testosterone and HGH in the body, both of which are necessary for muscle growth throughout your entire body—not just your legs.

Squats are also, arguably, one of the most functional exercises out there. Think about how much you squat throughout your everyday life: getting up and down from your bed and couch, sitting in your office chair, and more. If your leg muscles aren’t up to snuff, you’re going to fill the ramifications.

That said, you’ll be wasting your time if you make some of the most common squat mistakes around. Most of these mistakes are probably the reasons why many “don’t do squats” — you know, the people who say it’s bad for their knees or back.

But with any complex exercise, there’s a lot of room for error and the squat is no exception. Here are the top 10 mistakes people make with squatting, why they’re bad and exactly what you need to do to avoid them.