Strength is the motor capacity that a muscle, or a group of muscles, can exert in an action to overcome or oppose an external load. Strength training is then the set of physical exercises in which the muscles exert their activity against an external load to induce contraction, thus increasing anaerobic resistance and their very size. Exercises usually involve using weights, but they can also take a variety of different forms in which the technique is more important than the speed of execution. Training is then typically progressive, i.e. it involves increasing muscular strength through constant increases in workload thanks also to equipment developed to act on specific muscle groups.

Proper strength training provides significant functional benefits including stronger bones, muscles, tendons and ligaments, improved joint function, reduced risk of injury, increased metabolism, and improved cardiac function.

In the sports field, the concept of strength is closely linked to that of power which probably remains the most widely measured magnitude in any motor activity. The force produced by the muscles in fact results in the movement of the joints, which takes place in a certain period of time. The result of the association of these variables is the power magnitude, which is the product of the force generated and the speed of movement (F x v). To improve sports performance it is therefore essential to increase the power expended and to do so one of the strategies is to increase the muscular energy potential by increasing the mass of the muscle.

Strength can be expressed in different forms: maximum force, explosive force, explosive-elastic force.

The maximum force is theoretically the highest force that the neuromuscular system can express with a voluntary maximum contraction. It depends on the type of contraction–eccentric, concentric or isometric–and also on the type of movement, in particular on the angle of the joint on which the muscle acts. Generally, reference is made to the maximum concentric force.

Explosive force is classically defined as the ability to generate very high forces in the unit of time starting from a static position. An example of the expression of this force is the squat jump.

Explosive elastic force, on the other hand, is defined as the ability to achieve a considerable expenditure of strength during a muscle stretching/shortening cycle, that is during an eccentric contraction immediately followed by a concentric contraction. An example is the counter-movement jump. When defining a workout, you need to take into account the type of strength you want to increase when choosing the best exercise protocol.

Strength training is usually associated with lactate production, which can become a limiting factor in physical performance. However, regular exercise leads to musculoskeletal adaptations that may prevent the increase in the levels of this substance. For this reason it is important to measure the performance of the individual subject, in order to choose the workloads better: all this can avoid forcing the muscles too much and obtaining undesirable effects.

Using the Gyko inertial sensor enables evaluating and monitoring muscular strength over time.

When the goal of training is to optimize performance, it becomes crucial for every sportsperson to measure and analyze the improvement in their results in an objective and accurate way. For this reason, the sensor also enables estimating the muscular profile curve and the maximum value that are fundamental to correctly set up training for the development of strength and power (see fig 1).

Figure 1 The image shows a screenshot of the GykoRepower software at the end of a muscle profile estimation test. The data obtained will permit choosing the appropriate workloads to achieve a goal.