You are never too old to take exercise.

Exercise will not restore your youth, but it may restore your vigour; and the right exercises, done regularly in the right way, i.e. appropriate to your age and physical condition, will make you fit and keep you fit. 

Sep Meyer brings the benefit of his own experience to bear on advice and injunctions to all Third Agers, from 50 years of age through their nineties, on how to improve and maintain their muscles and endurance, whether to embark on a strenuous cycling or jogging programme, or simply to be able to lift a dishcloth and do the washing up for themselves.