Strength training is the use of resistance to muscular contraction to build the strength, anaerobic endurance, and size of skeletal muscles. When properly performed, strength training can provide significant functional benefits and improvement in overall health and well-being, including increased bone, muscle, tendon and ligament strength and toughness, improved joint function, reduced potential for injury, increased bone density, a temporary increase in metabolism, improved cardiac function, and elevated HDL (good) cholesterol. Training commonly uses the technique of progressively increasing the force output of the muscle through incremental increases of weight, elastic tension or other resistance, and uses a variety of exercises and types of equipment to target specific muscle groups. The obvious benefit of strength exercise is building strength, tone, and firmness. But there are other benefits too — strength increases your metabolism, as well as your energy and fitness levels. It even improves your balance and coordination.