Squats are the most efficient way to strengthen all your muscles from the waist down. What I tell my patients and the people I train is that if you have a strong butt, you have a happy life.
That's because squats strengthen your glute muscles particularly, and the glute muscles are the biggest, strongest muscles in the body — they're your biggest power generator.
Done properly, squats take the pain out of your hips: The glute muscles are external rotators and they take the pressure off the hip joint. So if you have achy hips or arthritic hips, stronger butt muscles actually literally open up the hip joint and take the pressure off the hip pinching.
But if you don't do them right, squats can actually put a lot more pressure on the joint, which can be quite painful. A proper squat shouldn't cause any knee or butt pain.
Here's how to do it better:
Turn your feet out. If your feet are not opened up, you don't open up the hip joints.
Squat like you're sitting in a chair. It's crude, but sitting on the toilet is the best image.
Keep your chest forward — think of your sternum pointing straight ahead.
Come down until your knee makes a right angle. (Turning your feet out will allow you to come down farther without pain.)
Hold your arms out straight with your hands in front of you.
As you get better, put your hands behind your head for a harder variation.
Do three sets of 10 reps. For a more advanced move, try a plyometric squat jump.