In strength training, the squat is a compound, full body exercise that trains primarily the muscles of the thighs, hips and buttocks, quads (vastus lateralus medialis and intermedius), hamstrings, as well as strengthening the bones, ligaments and insertion of the tendons throughout the lower body. Squats are considered a vital exercise for increasing the strength and size of the legs and buttocks, as well as developing core strength. Isometrically, the lower back, the upper back, the abdominals, the trunk muscles, the costal muscles, and the shoulders and arms are all essential to the exercise and thus are trained when squatting with proper form.

Squats are a competitive lift in powerlifting.

Gluteus Maximus (glutes), Quadriceps (quads), Hamstrings

The movement begins from a standing position. Weights are often used, either in the hand or as a bar braced across the trapezius muscle or rear deltoid muscle in the upper back. The movement is initiated by moving the hips back and bending the knees and hips to lower the torso and accompanying weight, then returning to the upright position. The squat can continue to a number of depths, but a correct squat should be at least to parallel (where the hips have descended to the same level as the knees, so that a line between the knee and hip joints would be parallel with the floor). Squatting below parallel qualifies a squat as deep while squatting above it qualifies as shallow. Correctly performed full squats (as demonstrated by olympic lifters in training and nearly all competitive lifters) are much safer on the knees and remove pressure from the lower lumbar region.