Blog 2 (Strength and Power)
Types of Contraction
All types of strength are a result of individual muscle fibres contracting, a muscle fibre contracts fully or not at all, the number of muscle fibres that contract simultaneously define the amount of force a muscle can produce and whether that muscle can overcome, maintain, or slowly lower the load it's working against.
If the force generated by the muscle fibres is greater than the load, then the entire muscle length will shorten and the load will move, this is called a Concentric Contraction.
When the load is greater than the force produced by the muscle fibres the muscle will lengthen, this is called an Eccentric Contraction, even though the muscle as a whole is lengthening, individual fibres are still contracting trying to resist the load.
Concentric/Eccentric contractions are collectively known as Dynamic contractions. When the force exerted by the fibres is equal to the load no movement takes place, this is called an Isometric Contraction. This of special interest to climbers as this type of contraction is very common in climbing: the fingers contract isometrically to maintain grip on a hold, the arms and torso contract isometrically to lock-off and reach. Other sports are primarily concerned with speed and dynamic (concentric/eccentric) strength, and consequently there has been a much greater amount of research conducted into the effects, methods, and consequences of dynamic training for athletic improvement, compared with comparatively little for isometric training for climbing.
When a muscle contracts at speed against a load this is known as Power. Sprinting, throwing, and jumping are all examples of power. The term power or powerful is often used inappropriately in climbing to describe any move that is hard. A dyno is a good example of a power move, the term Power Endurance is frequently used to describe a short section of intense climbing, when literally in sports science terms it would mean the ability to endure a number of consecutive dynos.