The growing formative period of life is the time for good
physical development. Whatever is gained and fixed then is
permanent, as it becomes a part of the physiological habits of
the individual. The years before twenty decide the future
energy stores, and the capacity to endure. Every function
enlarged, every gain of power, is additional storage room for
energy, to be drawn upon in the coming days of adult stress.

Good physical development not only gives strength and skill in
the use of the body, but develops a physiological habit of
surplus power that may be called quantity of energy. Life is
not alone in quality, in delicacy of adjustment, in accuracy,
in fineness of feeling; it is also in quantity. The poet who,
with frail physique and feeble pulse, sits in his quiet retreat
and puts his fine fancies into the rhythms of verse has
quality. But in the stress and rivalry of life that awaits the
majority of men, there is a need for quantity of energy, such
as enabled a Washington or a Caesar or a Napoleon or a
Wellington to shoulder his way through difficulties. These men
combined quality with quantity and this combination may make,
and often does make, the life of masterful achievement. The
quantity of energy in us average men may make the difference
between success and failure.

Many men fail in life for lack of staying power, for lack of
that kind of endurance that is furnished by having power in
reserve.

The strong, confident person who has strength to spare,