What we know as old age is a disease and like many other diseases it is progressive.
As we advance in years, the primal cause of aging increases; it is due to sedimentary deposits in the arterial and venous structures.
If the formation of these deposits is not checked, other parts of the system will later directly suffer, and will indirectly result to physical deterioration.
Under these conditions, the elasticity of youth is replaced by inelasticity of old age.
The only difference between a young body and an old one seems to be the elasticity of the former and the inelasticity of the latter.
Scientists who may criticize this statement will probably cite various other causes of age.
But it is undeniable that, as we advance in years, these ever increasing deposits result in arteriosclerosis; that is, a clogging up of the arteries by chalky deposits, the final result being general physical deterioration.
We cannot stop old age; neither can we transform an old body into a very young one.
But age can certainly be deferred.
To know how to keep physically young, you should know why you grow old.
The human anatomy is composed of millions of minute microscopic bodies which science terms cells.
Having come into being, these minute cells live their brief life and then die just as you and I must die.
And having become dead, matter must be eliminated from the system.
If not, they clog up the body and impede its functions.
Under these circumstances it rapidly deteriorates, the muscles that are not being properly nourished shrink and the signs of age appear.
If this clogging waste matter can be eliminated, then the conditions of youth will return.
This can be accomplished, as I have stated, in the alternate contraction and relaxation of the muscles.
In that way you force out from the body any waste matter that may have deposited into the venous and glandular system and it is then carried off by the ordinary bodily excretions.
Any muscle or set of muscles so exercised will increase in size, strength and elasticity, and will finally be practically rejuvenated.
This being true of one muscle, it is true of all.
And as all parts of the body are in sympathy with each other, any adjacent gland or organ will be benefited.
Therefore if all parts of the structure are so exercised, a general rejuvenation of the body can be achieved.
But in considering the causes of old age there is also another very important factor to be taken into consideration, and that is, the condition of the glandular function.
In old age there is usually inactivity in this direction, defective assimilation being therefore a marked characteristic of advanced years.
With that condition there is a loss in flesh and while it exists, it is impossible to build up the body.
The remedy lies in general muscular activity.
If the exercises are practiced using all the muscles of the body, this will stimulate all glandular action and will make the secretion, or excretion, function properly; thus assimilation will be improved which could lead to a healthier body.
The list of old men, thinkers, writers, statesmen and orators, who have achieved their greatest successes in advanced years, is too long to recite, but the secret of their success in every case was, that they kept busy.
There is an old German proverb, "If you rest you rust.
" It is true, and if you would be healthy and you want to prolong your life, don't get into a rusty condition, either mentally or physically.
If you do, then, like any other piece of machinery, your term of usefulness being past, you will be relegated to the junk pile and your stay in this earth will be shortened.
There is a close sympathy between the mind and the body and if either deteriorates the other will speedily share in its deterioration.
Therefore, keeping active mentally as well as physically is the great secret towards overall fitness and longevity.