CARDIOVASCULAR BENEFITS AND POTENTIAL HAZARDS OF PHYSICAL EXERCISE
IN ELDERLY PEOPLE^*

^*Doctoral dissertation presented on the 11^stof December 2004 at the Agora Center, Jyväskylä, Finland by permission of Faculty of Medicine of the University of Kuopio.

Large and consistent beneficial effects with few adverse effects have been found in relation to physical exercise in selected samples of elderly subjects. However, thus far, it has not been confirmed to what extent the effects of physical exercise among elderly people are beneficial or even harmful in population-based studies. Additionally, the role of exercise testing among elderly people remains unclear. Firstly, the effects of prolonged physical training on cardiovascular fitness in 66-85-year-old women were examined in a cross-sectional study. Secondly, the predictive value of exercise-test status and results, including exercise capacity for survival, were studied in 75-year-old men and women. Thirdly, the effects of an endurance and strength training programme were examined in women aged 76 to 78 years in a population-based randomized controlled trial. Finally, the cardiac-adverse effects of acute exercise in the form of a cycle ergometer test were clarified in 75-year-old men and women. In the maximal exercise tests the mean peak oxygen uptake was respectively 26.2 and 18.7 ml·kg^-1·min^-1 among the physically active and less active control women. High cycling power (Watts per kg body weight) in the completed ergometer test was associated with decreased risk for death (multivariate HR 0.20; CI 0.08 - 0.50). The 18-week strength training resulted in a 9.4% increase in peak oxygen uptake while the endurance training improved peak oxygen uptake by 6.8%. A significant increase in cycling power in W/kg was found in the strength and endurance training groups compared to controls. Five cases of cardio- or cerebrovascular health problems emerged in the exercise training groups. These health problems were not directly related to physical exertion. In the final study 23 and 7% of the exercise tests in men and women, respectively, were prematurely terminated because of cardiac arrhythmia or ST segment depressions. Using various study designs and methods the effects of physical training on cardiovascular fitness were found to be beneficial among the four different samples of elderly people. High exercise capacity was found to be strongly and independently associated with decreased mortality among elderly men and women. Exercise testing provides information on the risk of death that is incremental to clinical data and traditional risk factors for death. Cardiovascular monitoring during exercise testing is recommended as a safety precaution. Cardio- or cerebrovascular health problems can occur during exercise training programmes involving elderly people, although they may not be directly related to physical exertion. The dose-response relationships in relation to physical exercise among elderly people remain in need of further clarification in population-based trials.

KEY WORDS: Benefits and hazards of exercise, cardiovascular fitness, older people, exercise testing, predictive value, arrhythmia, ST segment depressions.