“Use it or Loose it“
This phase has become something of a cliche but unlike a lot of exercise “wisdom” it happens to be true – and it applies to just about every aspect of your development – speed, strength, flexibility, stamina etc.
If you do not work on improving or at least maintaining physical attributes – for example, flexibility, speed or strength - over the passing of time your ability in these area will decrease.
However, with a balanced training programme you will use all your physical attributes – and therefore you will maintain these over the course of years.
Not convinced? William Sichel is currently 56 years old and over the past few years he has increased his strength, flexibility, average running speed and endurance capacity – he is fitter now than he was 20 years ago.
Work on these areas of your training and rather than accepting that decline with age is “inevitable” you will find that you can improve too.