Unluckily some people are less successful in performing a trainingprogram than others.
One of the factors, causing this is the age. Although in particular in the last 10-15 years, studies could reveal the incredible potential of older people, to improve their physical shape by training, we can't ignore that a 20-year old has another physical material and reserve than a 80-year old man.
But if we look in more detail, we can differenciate between some different types of characters, how to deal with "disability":
First we have the very ambitious person, who did sports over his whole life, performed competitions and is suddenly confronted with a disease that disables him massively. The most risk for this group is, never coming back to a personal satisfactory sportslevel, because they will never learn to dose their physical input. They also set too ambitious expectations, which very often can't be reached, what leads to just more frustration. Here the other personality, that feels better with beeing more cautious, has definitely a better prognoses, because this fine body-awareness is an extremely important precondition, to find back to normal life without major restrictions.
But in most cases we can see, that even professional sportsmen, who came to us primarily with acute discpain, turn out to have major muscular deficits in at least some of the bodystabilizers as well as in the deep, small spinemuscles. As we have the possibility to measure strength and coordination very exactly, we could confirm the international data that normal training, even on fittness machines are not able to stabilize the particular muscles, which protect us from getting another period of nerverootpain or pain out of the facetjoints.