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Dr. Ramsay is a Fellow, Division of Geriatric Medicine, St. Louis University School of Medicine. Dr. Ramsay reports no commercial conflict of interest.
Exercise can be defined as sustained physical activity which is planned, structured and involves repetitive movement aimed at improving or maintaining one or more components of physical fitness.
Data drawn from the National Health Interview Survey, Federal Centers for Disease Control (CDC), and National Health Center for Health Statistics in 1995, indicated that approximately 16 percent of Americans engaged in regular vigorous physical activity three days per week. Twenty-five percent were completely sedentary. In 1997 data reported to the National Health Interview Survey showed a decrease in physical inactivity with aging.(1)
Physical Activity By Age Group.
Adapted from The National Health Interview Survey 1997.
The Surgeon General's report on physical activity and health in July 1996 concluded that regular sustained physical activity could substantially decrease the risk of developing heart disease or dying from it. The report hoped to motivate Americans to engage in regular physical activity. Prescribing exercise should be regular practice for all clinicians and the following includes guidelines for doing so.
Exercise can be divided into four main categories:
Resistance TrainingResistance or strength training builds muscle strength and mass.(2)(3)(4)(5)(6)(7) Nelson et al. showed that age-related loss of strength, muscle mass and bone density, especially in women, could be lessened by strengthening exercise begun in middle or old age.(8) Gains in muscle strength in frail elders may enhance balance,(8) aerobic capacity,(9)(10) flexibility,(11)(12) and performance-based tests of functional limitation, such as gait velocity, stair climbing and the get up and go test.(13)(14)(15)(16)(17) Most low to moderate intensity resistance training programs, however, do not substantially improve strength.
Psychological responses were also seen with resistance training. These included improved morale and reduced depressive symptoms. In two studies, high intensity progressive resistance training and aerobic training, reduced depression to a similar extent as medications.(19)
Resistance training involves use of weights in isometric and isokinetic training. Most programs for elders utilize free weights, elastic bands or body weight to provide resistance. Training protocols are based on weight and number of repetitions. The weight used is determined by the maximum weight the person can lift just once (1-RM or one repetition maximum). Common protocols use 2 to 3 sets of 8 to 10 repetitions each. Resistance training itself has different subgroups.
Progressive resistance training may start at 75% of the 1-RM with an increase in resistance with each set. Fixed resistance training uses the same weight for all sets. Progressive rate training uses the same weight but increases the rate with each set.
Aerobic TrainingAerobic training, or endurance exercise, improves aerobic capacity. It involves activity aimed at raising the heart rate to a target of about 60% to 90% of maximum predicted heart rate. In the elderly, your program or trainer need to be aware of age-related physiological changes and use the Borg Scale of Perceived Exertion,(20) to set the maximum activity level. The scale grades perception of exertion (see Table 2). Aim for 11-17 on the scale depending on the mode of exercise.
The Borg Scale of Perceived Exertion.
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