Types

Resistance training

Main article: Resistance training

Resistance training as a term, is actually applicable to all forms of strength training, as resistance can come from a variety of forces, including overcoming inertia, momentum, or acceleration from gravity. In a more specific usage (which excepts weight resistance training) it refers to a form of strength training in which each effort is performed against a specific opposing force generated by resistance (i.e. resistance to being pushed, squeezed, stretched or bent). Exercises are isotonic if a body part is moving against the force. Exercises are isometric if a body part is holding still against the force. Resistance exercise is used to develop the strength and size of skeletal muscles. Properly performed, resistance training can provide significant functional benefits and improvement in overall health and well-being. The goal of resistance training, according to the American Sports Medicine Institute (ASMI), is to "gradually and progressively overload the musculoskeletal system so it gets stronger." Research shows that regular resistance training will strengthen muscle and increase bone mass^{[citation needed]}.

Weight training

Main article: Weight training

See also: Bodyweight exercise

Weight and resistance training are popular methods of strength training that use gravity (through weight stacks, plates or dumbbells) or elastic/hydraulic resistance to oppose muscle contraction. Each method provides a different challenge to the muscle relating to the position where the resistance to muscle contraction peaks. Weight training provides the majority of the resistance at the initiating joint angle when the movement begins, when the muscle must overcome the inertia of the weight's mass (however, if repetitions are performed extremely slowly, inertia is never overcome and resistance remains constant). In contrast, elastic resistance provides the greatest opposition to contraction at the end of the movement when the material experiences the greatest tension while hydraulic resistance varies depending on the speed of the submerged limb, with greater resistance at higher speeds. In addition to the equipment used, joint angles can alter the force output of the muscles due to leverage.

Isometric training

Main article: Isometric exercise

Isometric exercise, or "isometrics", is a type of strength training in which the joint angle and muscle length do not change during contraction. Isometric exercises are opposed by a force equal to the force output of the muscle and there is no net movement. This mainly strengthens the muscle at the specific joint angle at which the isometric exercise occurs, with some increases in strength at joint angles up to 20° in either direction depending on the joint trained.^[3] In comparison, isotonic exercises strengthen the muscle throughout the entire range of motion of the exercise used.

Basic principles

The basic principles of strength training involve a manipulation of the number of repetitions (reps), sets, tempo, exercises and force to cause desired changes in strength, endurance, size or shape by overloading of a group of muscles. The specific combinations of reps, sets, exercises, resistance and force depend on the purpose of the individual performing the exercise: sets with fewer reps can be performed using more force, but have a reduced impact on endurance.

Strength training also requires the use of 'good form', performing the movements with the appropriate muscle group(s), and not transferring the weight to different body parts in order to move greater weight/resistance (called 'cheating'). Typically failure to use good form during a training set can result in injury or an inability to meet training goals - since the desired muscle group is not challenged sufficiently, the threshold of overload is never reached and the muscle does not gain in strength. There are cases when cheating is beneficial, as is the case where weaker groups become the weak link in the chain and the target muscles are never fully exercised as a result.

The benefits of strength training include increased muscle, tendon and ligament strength, bone density, flexibility, tone, metabolic rate and postural support.

Terminology

Strength training has a variety of specialized terms used to describe parameters of strength training:

• Exercise - different exercises involve moving joints in specific patterns to challenge muscles in different ways
• Form - each exercise has a specific form, a topography of movement designed to maximize safety and muscle strength gains
• Rep - short for repetition, a rep is a single cycle of lifting and lowering a weight in a controlled manner, moving through the form of the exercise
• Set - a set consists of several repetitions performed one after another with no break between them with the number of reps per set and sets per exercise depending on the goal of the individual. The number of repetitions one can perform at a certain weight is called the Rep Maximum (RM). For example, if one could perform ten reps at 75 lbs, then their RM for that weight would be 10RM. 1RM is therefore the maximum weight that someone can lift in a given exercise - i.e. a weight that they can only lift once without a break.
• Tempo - the speed with which an exercise is performed; the tempo of a movement has implications for the weight that can be moved and the effects on the muscle.