Squats are a great symetrically loaded exercise for building the leg and butt muscles. Squats are considered by the Reciprocal Energy Fitness program to be one of the five basic essential body strengthening exercises. Getting up from a chair and picking up something from the floor both require this basic life movement. Also this is one leg exercise that works many different muscles.
When doing a squat one should keep the weight in the heels, abs drawn in, hips back, the rib cage lifted, and eyes forward. There are several versions of squats, some of which engage certain muscles more than others. Squats can be done using ones body weight or performed incorporating different tools.