Behold: The humble body weight squat. Not only will dropping it like it’s hot strengthen your quads, hamstrings, and glutes, adding squats to your regular workout routine could mean fewer knee injuries. And you’ll increase your bone mass which will help you avoid osteoporosis as you age. Plus, one study shows that increasing lower body strength can help you be a better runner. We’ve rounded up 40 variations in four different categories—bodyweight, plyometric, weighted, and equipment—for your squatting pleasure (or pain). To read more click here!