BETWEEN THE SEXES
People vary in their physical makeup. Each body reacts differently
to varying degrees of physical stress, and no two bodies react
exactly the same way to the same physical stress. The following paragraphs
describe the most important physical and physiological differences
between men and women.
The average 18-year-old man is 70.2 inches tall and weighs
144.8 pounds, whereas the average woman of the same age is 64.4
inches tall and weighs 126.6 pounds. This difference in size affects
the absolute amount of physical work that can be performed by
men and women.
Men have 50 percent greater total muscle mass, based on weight,
than do women. A woman who is the same size as her male counterpart
is generally only 80 percent as strong. Therefore, men usually
have an advantage in strength, speed, and power over women.
Women carry about 10 percentage points more body fat than
do men of the same age. Men accumulate fat primarily in the back,
chest, and abdomen; women gain fat in the buttocks, arms, and
thighs. Also, because the center of gravity is lower in women
than in men, women must overcome more resistance in activities
that require movement of the lower body.
Women have less bone mass than men, but their pelvic structure
is wider. This difference gives men an advantage in running efficiency.
HEART SIZE AND
The average woman's heart is 25 percent smaller than the average
man's. Thus, the man's heart can pump more blood with each beat.
The larger heart size contributes to the slower resting heart
rate (five to eight beats a minute slower) in males. This lower
rate is evident both at rest and at any given level of submaximal
exercise. Thus, for any given work rate, the faster heart rate
means that most women will become fatigued sooner than men.
Women generally are more flexible than men.
The lung capacity of men is 25 to 30 percent greater than
that of women. This gives men still another advantage in the processing
of oxygen and in doing aerobic work such as running.
RESPONSE TO HEAT
A woman's response to heat stress differs somewhat from a man's.
Women sweat less, lose less heat through evaporation, and reach
higher body temperatures before sweating starts. Nevertheless,
women can adapt to heat stress as well as men. Regardless of gender,
people with a higher level of physical fitness generally better
tolerate, and adapt more readily to, heat stress than do less
For information on a wide array of Women's Health issues, visit Women's Health Zone.