Above-threshold stimuli are required for the development and maintenance of physical performance. Loss of function and performance occur if these stimuli are absent for a longer period.
The decrease of physical performance begins from the third decade and is caused by decreased adaptability and generally reduced physical capacity.
Between the ages of 40 and 50 years (Letunow 1973, 211; Noder 1975, 11; Eitner 1977, 208) or between 50 and 55 years (Bringmann 1977, 663) there is a loss of performance (rapid decline in the performance and functioning of the body).
It is the unanimous view of many scientists that this loss of performance can be slowed down by physical training!
Among lifelong practitioners of endurance training, the loss of performance only starts to occur from the age of 70! (Büschke 1966, 32; Haas et al. 1970 1506; Pollock et al. 1973, 246)
Training has a decisive effect on the form and function of the body and indeed to a greater extent than age! (Jokl 1975, 14)
The healthy older person basically responds to training stimuli in the same way as the healthy younger person – but with quantitative differences. (Jokl 1970, 35/39; Badtke 1982, 116)