Weight training is a common type of strength training for developing the strength and size of skeletal muscles. It uses the force of gravity (in the form of weighted bars, dumbbells or weight stacks) to oppose the force generated by muscle through concentric or eccentric contraction. Weight training uses a variety of specialized equipment to target specific muscle groups and types of movement.

Weight training differs from bodybuilding, weightlifting, powerlifting and strongman, which are sports rather than forms of exercise. Weight training, however, is often part of the athlete's training regimen.
Strength training is an inclusive term for all types of exercise devoted towards increasing muscular strength and size (as opposed to muscular endurance, associated with aerobic exercise, or flexibility, associated with stretching exercise like yoga or pilates, though endurance and flexibility can improve as a byproduct of training).