boy and ascribes his development chiefly to systematic training.

We have space but for two reports believed to be typical. Enebuske
reports on the effects of seven months' training on young women
averaging 22.3 years. The figures are based on the 50 percentile
column.

----------------+--------+----------------------------------+--------
| | Strength of |
|Lung | | | |right |left |Total
|capacity| legs |back |chest|forearm|forearm|Strength
----------------+--------+------+-----+-----+-------+-------+--------
Before training | 2.65 | 93 |65.5 | 27 | 26 | 23 | 230
After six months| 2.87 | 120 |81.5 | 32 | 28 | 25 | 293
----------------+--------+------+-----+-----+-------+-------+--------

By comparing records of what he deems standard normal growth with that
of 188 naval cadets from sixteen to twenty-one, who had special and
systematic training, just after the period of most rapid growth in
height, Beyer concluded that the effect of four years of this added a
little over an inch of stature, and that this gain as greatest at the
beginning. This increase was greatest for the youngest cadets. He
found also a marked increase in weight, nearly the same for each year
from seventeen to twenty one. This he thought more easily influenced
by exercise than height. A high vital index ratio of lung capacity to
weight is a very important attribute of good training. Beyer[1] found,
however, that the addition of lung area gained by exercise did not
keep up with the increase thus caused in muscular substance, and that
the vital index always became smaller in those who had gained weight
and strength by special physical training. How much gain in weight is