Beginning well before “young” old age, participation of men in competitive aerobic activities drops sharply. In dropouts, the role of habitual aerobic exertion in primary prevention of cardiovascular morbidity is diminished or absent. After age 65, participation in competitive activities, such as distance running, is markedly reduced. At that stage, muscular force and aerobic capacity are noticeably on a downward slope, arterial wall becomes stiffer, and musculoskeletal injuries heal slower. As well, age-related arterial dysfunction is greater when associated with sedentary lifestyle compared to a physically active lifestyle.9
This study points to health benefits of higher levels of aerobic exercise in the elderly runners. Compared to age-matched healthy sedentary controls, athletes had superior health indicators in all categories except for lipid profile (including HDL) and systolic blood pressure. These benefits, however, were more apparent when individuals are stressed. In the 10-year longitudinal study, the effect of aging on athletic performance and health indicators became evident. The high level of aerobic fitness was unable to appreciably slow deterioration of LV diastolic function. Cardiac valves stiffened and became progressively more regurgitant. Nevertheless, LV diastolic dimension and ejection fraction diminished presumably due to reduced training mileage and frequency of competitive events (reversal of “athletes heart” effect).
In the majority of our athletes, the decrease in achievement level is attributed to normative aging and appears to occur exponentially with increasing age. Drop in oxygen utilization and quicker muscle fatigue are major contributing factors. Additionally, LV diastolic function diminished (reversal of E/A ratio). Athletes were compensating for decreased diastolic filling by amplifying atrial contraction (A-wave), especially during strenuous exercise.
Maintaining physical fitness at older ages is hindered by progressive musculoskeletal deterioration and drop in tissue oxygen utilization. Consequently, pursuit of fitness levels achievable by sustained increases in heart and respiratory rates as a means of primary disease prevention will have limited appeal. Age group competitions offered by annual Senior State Games and Senior Olympics have the potential of increasing athletic participation, but need to be better promoted by the media. In 2005, 86 million Americans walked regularly for exercise.10
Runners in this study were competitive amateur athletes. Health benefits were considered secondary to their pursuit of fitness and generally taken for granted. Two participants (ages 80 and 83), while still athletic, experienced serious cardiovascular complications and were excluded from the final testing. Elderly men who score well on treadmill stress test are not necessarily immune from unexpected cardiovascular morbidity.11
Absolute values of diastolic parameters are important in defining LV compliance, especially when differentiating between athletes’ heart and cardiomyopathy.12
Test results were made available to each participant’s personal physician. Most athletes declined treatment of borderline or abnormal findings for fear of interfering with race performance.
There are some potential difficulties with our study. This study was based on a small segment of a large metropolitan population and its statistical power is low. The pool of volunteers suitable for our exercise protocol was limited. Assembling a larger cohort of elderly athletes and especially controls for a long-term treadmill follow-up is expected to remain a formidable task. However, given these difficulties some parameters of cardiovascular fitness remain preserved in the elderly elite athletes.