Education: Muscle Contractions

There are three different types of muscular contraction which can occur in most muscle within the body.

Concentric muscular contraction (b)

During concentric contraction the muscle gets shorter under tension.

Specific Training Uses for Concentric Work

Weight/resistance training relies heavily on concentric movements. The muscles being utilised will also be strengthened throughout the whole range of motion the joint is trained in. This will result, when training with appropriate weight/resistance, in an increase in physical strength. It is therefore important when training for a particular activity or sport to make sure you use the full range of movement possible to get the best performance increase throughout the whole movement.

Eccentric muscular contraction (c)

During eccentric contraction the muscle gets longer under tension.

Specific Training Uses for Eccentric Work

As stated above weight/resistance training also relies heavily on eccentric movements with muscles being strengthened throughout the whole range of motion. It is important to make sure you use the full range of movement when training to get the best performance increase throughout the whole movement. The muscle is always stronger during an eccentric contraction so eccentric work (negative reps) can be particularly useful when training for strength increases. A good example of where the gains in strength could be utilised in sport would be during a game of rugby where having a strong grip when an opponent is trying to break away from a tackle is extremely important.

Isometric muscular contraction (a)

During concentric contraction the muscle stays the same length under tension.

Specific Training Uses for Isometric Work

An isometric contraction strengthens the muscle at the specific joint angle at which the isometric exercise occurs (with some lesser gains in strength also occurring at proximal joint angles).  This sort of training, building strength in one set position, can be useful when training for a wide variety of different sports. It is important though to concentrate on replicating the fixed position very closely to achieve the strength gains at the appropriate joint angles. A good example would be a barbell fingertip hold to build the strength needed in the fingers and hands needed for high level rock climbing.