Physical Development during Midlife
By the time people turn forty, they become aware of the age-related changes occurring in their bodies. Cardiac output, the amount of blood pumped by the heart, decrease noticeably, and the walls of the large arteries lose some degree of flexibility. As a result, less oxygen can be delivered to working muscles within a given period of time, and even people who exercise regularly become aware of some decline in this respect in this respect. They simply can’t do quite as much as they once could. The performance of other major organ systems, too, declines, and an increasing number of people experience difficulties with digestion. Other changes are readily visible when middle-aged people look in the mirror: thinning and graying hair, bulges and wrinkles in place of the sleek torso and smooth skin of the youth. Huge individual’s differences exist in the rate at which such changes occur, however. While some persons in their forties and fifties closely match common stereotypes concerning middle age, others retain much of their youthful appearance and vigor during this period of life.
Among the most dramatic changes occurring during middle adulthood is the climacteric- a period of several years during which the functioning of the reproductive system and various aspects of sexual activity changes greatly. Although both sexes experience the climacteric, its effects are more obvious for females, most of whom experience menopause-cessation of the menstrual cycle- in their late forties or early fifties. During menopause the ovaries stop producing estrogens and many changes in the reproductive system occur: thinning of the vaginal walls, reduced secretion of fluids that lubricate the vagina, and so on. Once females stop releasing ova, pregnancy is no longer possible. In the past, menopause was considered in some Western societies to be stressful process. Some women do find hot flashes- bursts of heat and perspiration that occur in what seems to be an unpredictable manner- somewhat unpleasant. However, many women do not experience such symptoms at all or experience them to a minimal degree. There is growing recognition of the fact that cultural factors play a key role in reactions to menopause and its effects, and that for most women it is definitely not a disturbing or anxiety-provoking event.
After menopause women become more susceptible to osteoporosis, a decrease in bone mass and strength. To avoid such effects, an increasing number of women in developed nations undergo hormone replacement therapy (HRT), which supplements estrogen and progesterone, usually through daily pills or transdermal (skin) patches. Such treatment may reduce a woman’s risk of osteoporosis and heart disease, but it may also be related to increased risk of breast cancer, so debate continues as to whether the benefits of HRT more than offset its potential costs.
Among men the climacteric involves reduced secretion of testosterone and reduced functioning of the prostate gland, which plays role in semen formation. In many men the prostate gland becomes enlarged, and this may interfere not only with sexual functioning, but with urination. Men often experience reduced sexual drive at this time of life; but although sperm production decreases, many can still father children.
So far, this picture of physical change during midlife may sound discouraging strength, beauty, and vigor all decline during this period. But, remember: while some physical decline is inevitable during the middle decades of life, both the magnitude and the rate of such decrements are strongly influenced by the individual lifestyle. In fact, growing evidence suggests that while we can’t stop the clock of ageing altogether, we can slow it down appreciably. In other words, we can achieve successful aging- experience minimal physiological losses in many functions when compared to younger persons.