For both men and women, regular exercise offers weight loss, reduced levels of harmful cholesterol, fewer sick days and an improved self-concept. Those who exercise have less low backache, headache, anxiety, depression and fatigue. Weightbearing exercises build and maintain strong bones in both sexes. The points noted in this article concern the physical differences between men and women:
For some women, especially those with little body fat, too much exercise can reduce the levels of hormones (estrogen and progesterone) which control menstruation. The results may range from normal periods with no egg produced, to infrequent and light periods (oligomenorrhea), to no periods at all (amenorrhea).
For girls near puberty, the onset of periods may be delayed by intense exercise. Changes in the menstrual cycle can have an effect on fertility, although this usually only occurs with excessive exercise.
Most women report differences in performance during the menstrual cycle. This is supported by evidence that performance is not as good before the period and is best during the period.
Estrogen and progesterone help bone growth. If hormone levels are low for a long time, such as with very intense exercise, calcium can be lost from the bone. This loss is similar to that which occurs after menopause. It may result in broken bones, especially the spine and hips. More important, light or moderate exercise will improve bone strength.
The reason for exercise-related hormone changes are complex and not well understood. What is known is adverse changes from excessive exercise can be reversed with small reductions in training or small weight gains. Certainly women who have irregular periods, no matter what the cause, should see their doctor. Women who have a history of irregular periods could have their bone density measured to determine if there has been any associated bone loss.
Active women must maintain proper iron levels in the body. Iron is found in hemoglobin, which is in the red blood cells carrying oxygen from the lungs to the tissues. Iron is also an important part of many body proteins and cell components.
Women who menstruate risking having low iron because of the regular loss of blood (and therefore iron) which occurs each month. Very active women have an added risk because their bodies absorb less iron. They also lose iron with sweat and have a breakdown of red blood cells in some of the tissues.
Red meat provides the best source of iron. Any red meat and the dark meat of poultry provide a form of iron called heme-iron. This is more easily used than the iron found in vegetables and grains. It is most effective when combined with vegetable proteins. For example, split-pea soup with ham, or chicken soup with lentils are high-iron combinations. Vitamin C, plentiful in fruits, will also increase iron absorption. Some people who restrict meat from their diets are also counting calories. These people may cut back on other food groups which supply iron. One way to increase iron, especially if calories are being limited, is to choose breads, cereals and pasta with ‘enriched’ or ‘fortified’ on the label.
The single or combined effect of loss of iron through menstruation, exercise and diet restrictions may cause iron deficiency. The symptoms of low iron include tiring easily and poor performance. If iron stores become too low, anemia will result and the added symptoms of this include paleness, greater fatigue and shortness of breath. All women should eat a diet with enough iron (see table). It is also important that they have hemoglobin levels checked periodically by a doctor. For those at risk of low iron, the body’s iron stores should be measured.
A question often asked about women in sport is whether they are at higher risk of injury than men. This concern, without basis in fact, kept women from taking part in many sports until recently. For example, women were not allowed to compete in the marathon at the Olympics until 1984.
The body’s response to exercise is the same for both sexes. Each sport carries its own risk of injuries. Women are at no greater risk of these injuries than men and should be allowed to take part in any sport. If a training program is suited to the level of fitness, women are no more likely than men to suffer injury. Any sports injury should be treated promptly by a doctor.
One concern to women in sport is exercise during pregnancy. In this special case, pregnant women should discuss the exercise program with a doctor.
Exercise is key to good health for everyone. Women should take part in regular exercise and sport, not only for their health bt also for the pure pleasure of participation.