From the theoretical viewpoint, force may be referred to as both a mechanical characteristic and a human ability. In the former case force is the object of studies in mechanics, while in the latter it is the scope of physiological and methodical investigation in training.
Force as a Mechanical Characteristic
Consequently, an increase in strength may be achieved by changing one or both of these factors (m or a). Such changes result in quantitative alterations which must be kept in mind when developing strength. The following two equations used in mechanics may illustrate this point:
where Fmx is maximum force; mmx is maximum mass and amx means maximum acceleration.
In the first equation maximum force is developed by using the maximum mass (or load) possible, whereas the same result is achieved in the second equation by using the maximum speed of movement The force that an athlete can apply and the velocity at which he/she can apply it maintain an inverse relationship (which was demonstrated above). Hits is also true for the relationship between an athlete’s applied force and the time period over which one can apply it The gains in one ability is at the expense of the other. Consequently, although force may be the dominant characteristic of an ability, it cannot be considered in isolation because the afore-mentioned speed and time component will directly affect its application.
The force-velocity inverse relationship was demonstrated by Hill (1922) and Ralston et al (1949). An adaptation of Ralston’s force-velocity curve is illustrated by figure 102 which demonstrates, that when the mass is low, the acceleration is high given maximum effort by the participant As the mass increases (from baseball throw to shot put and weight lifting) the acceleration decreases, up to no movement at all (or static muscular contraction for mass heavier than one’s maximum force).
The magnitude of the force is directly related to the magnitude of the mass. This relationship is linear only at the beginning when the force increases as the mass of the moving object increases. A continuous elevation of a mass will not necessarily result in an equally large increase in applied force. Therefore, the per gram force which the athlete applies against a shot (shot putting in athletics) will be greater than that applied when he/she lifts a barbell. As suggested by Rorescu et al (1969), in order to put a shot of 7.250 kg 18.19 m an athlete displays a power of 6.9 h.p. (horse power) or 5147 Watts, while to snatch (weight lifting) 150 kg requires only 4.3 h.p, or 3207 Watts.