Exercise plays an important role in enhancing the quality of life of the older patient, although studies have shown that regular physical activity does not significantly lengthen life expectancy. Improved physiologic and psychological function helps to maintain personal independence and reduces demands for acute and chronic care services. This has significant economic benefits, as the resultant cost savings will likely cover the costs of a well-designed exercise program. Primary care physicians can help older patients to realize these benefits by encouraging them to increase their physical activity and by prescribing appropriate exercise regimens.
Shephard RJ. Exercise and aging: Extending independence in older adults. Geriatrics 1993; 48(May):61-64.
Dramatic increases in the 65- to 74-year-old and the over-85-year-old segments of the North American population have given rise to a new round of questions about the medical, social, and economic implications of increased physical activity in older adults.( n1) Primary care physicians are often called upon to answer questions patients have about the long- and short-term benefits of exercise and to prescribe appropriate exercise programs. Older patients may want to know, for example, whether they will live longer if' they exercise.
The purpose of this article is to discuss the impact of exercise upon absolute life expectancy, quality-adjusted life expectancy, and functional status (physiologic and psychological J, as well as the economic implications of exercise in this patient population.
Exercise and life expectancy
Absolute life expectancy. For the primary care physician treating the older adult, a patient's early history of exercise will probably not predict longevity, studies have shown. Early comparisons of university athletes with their sedentary peers failed to demonstrate any difference in longevity between the two groups.( n2) This was due in part to the selection of athletes for sport teams for their unusual body builds (which were not necessarily optimal in terms of survival), but mainly because the former athletes abandoned their active lifestyles after leaving school.
Montoye and associates found that middle-aged former athletes were overweight, inactive, and smoking and drinking more than their supposedly sedentary peers.( n2) Plainly, the lesson from this research is that the health benefits from exercise cannot he stored but depend entirely upon maintenance of a healthy lifestyle.
In another study, Karvonen and associates( n3) examined a group of athletes who continued with their exercise until they reached an advanced age. This study reported that Finnish cross-country ski champions lived an average of 3 to 4 years longer than their sedentary contemporaries, However, most of the skiers were lifelong nonsmokers, and this undoubtedly contributed to their greater longevity. Indeed, young adults who give tip a heavy cigarette addiction may lie adding as much as 8 years to their lifespan.
More recently, Paffenharger et al( n4) analyzed data on former Harvard alumni in a prospective study covering 22 years. They noted that regular physical activity was associated with a substantial increase in average lifespan. Following subjects through to age 80, they estimated a gain of more than 2 years if exercise was begun at an age of 35 to 39 years but a gain of only 0.4 years if begun between the ages of 75 and 79. The benefit persisted after adjustment of the data for other cardiac risk factors leg, cigarette smoking, excess body mass, and hypertension) but was observed only if the activity had continued throughout adult life. In fact, this study showed that it was better to have been inactive at college but active in old age than the converse.
The major determinant of longevity appeared to be the establishment of an appropriate increase of weekly energy expenditure. Some extension of lifespan was seen with an added weekly expenditure of 2 MegaJoules (500 koala, and the effect was maximized at an added weekly energy expenditure of 8 MegaJoules ( 2,000 kcal). The type of exercise was less critical, as many members of the active group apparently derived much of their added energy expenditure from very simple pursuits (eg, fast walking and stair-climbing), rather than from participation in organized sports.
Pekkanen et al( n5) observed similar results in Eastern Finland. In early old age, their active group had substantially better survival prospects than sedentary individuals, but by age 80, the percentages of active and inactive survivors were almost identical.
The implication of these findings is that regular exercise helps to avoid the premature deaths of middle age and early old age, but it does not increase the percentage of the surviving very old. Although the increased likelihood of survival in early old age initially may appear quite impressive, the value of this change must be qualified by the patient's reaction to the exercise regimen.