Static or isometric training – a discipline with a limited area of application.
In isometric (= static) muscle contractions, there is no change in the joint position, as the origin and insertion of the muscle on the bone neither move closer nor further apart.
One example is holding an object on an outstretched arm. Here, the shoulder muscle must work isometrically. In particular, muscles that constantly have to hold our body upright are largely used isometrically throughout the day, e.g. the back extensor muscles or the neck muscles. Even during dynamic strength training, where dumbbells and weight plates are moved, some muscle groups are always isometrically active in order to fix the posture and the neighboring joints.
However, one should only speak of isometric training if the main target musculature of the training exercise is isometrically stressed.
This is the case with some trunk exercises for the abdominal and back muscles, e.g. support and holding exercises in a prone position, in a four-foot stance or on a Pezzi ball. As mentioned above, the isometric form of contraction is typical for these muscles, but this does not mean that they should only be trained statically. In sport in particular, the spine is moved in a variety of ways, which is why dynamic trunk exercises are required.
Apart from the core muscles, isometric training only plays a major role in the training program in certain sports if prolonged holding work is sport-specific and performance-defining.
Examples include sports such as alpine skiing (downhill squat), shooting (holding the weapon) or gymnastics (elements such as cross-slopes or angular supports). Static muscle contractions also have a certain relevance in rehabilitative training if certain joint movements are painful or cannot be performed due to a lack of resilience.
Otherwise, dynamic muscle training is actually always preferable, as it has a more favorable effect on mobility, coordination, metabolic processes and long-term performance development.
Strength development also tends to be angle-specific, i.e. the transfer effects of isometric tensing at a 90° knee angle to other joint angles are only to be expected to a limited extent or not at all. In addition, isometric training is relatively monotonous, often not very motivating and associated with higher blood pressure increases. Finally, static muscle contractions lack the increased blood flow to the brain that is typical of dynamic muscle work. The advantages of isometric exercises – apart from the areas of application mentioned above – are above all an initially rapid gain in strength, short recovery times and a very low expenditure of time and training resources. Isometric exercises can be performed spontaneously almost anywhere if you contract against your own muscle strength (of a stronger muscle) or against solid resistance (e.g. walls, floor, door frame). The table below shows possible load norms for isometric training.
