Introduction Poor Sleep Quality Is a Common Problem among Mid- Dle-aged and Older Adults and Is Associated with Decrements

POOR SLEEP QUALITY IS A COMMON PROBLEM AMONG MIDDLE-AGED AND OLDER ADULTS AND IS ASSOCIATED WITH DECREMENTS IN LEARNING, MEMORY, AND ALERTNESS; REDUCED IMMUNE FUNCTION; AND DEPRESSION.1 A recent study suggests that too little or too much sleep may increase the risk of cardiovascular disease in women.2 Older men and women spend more time in bed than do younger people, but they get less sleep.3 In 1 study, 42% of healthy middle-aged women reported some type of sleep disturbance over the previous 6 months.4 The prevalence of sleep disturbances was higher among women with truncal obesity and those who did not take hormone replacement therapy after becoming postmenopausal.4 Physical activity and stretching are possible interventions to improve sleep. In a study of older men, fit individuals had shorter sleep-onset latencies and higher sleep efficiencies than did sedentary men.5 Nonrandomized interventions have reported improvements in the restactivity cycle,6 increases in slow-wave sleep,7 higher sleep efficiencies,810 and fewer awakenings8-10 with moderate-intensity exercise. One study, however, reported no change in sleep patterns after a 12-week exercise program in 9 unfit young women.11 Five randomized trials have examined some aspect of the effect of physical activity or stretching on sleep quality in older adults. Among 32 depressed men and women compared to controls, subjective sleep quality and sleep-onset latency significantly improved after 10 weeks of weight training.12 Another study, which compared 43 sedentary men and women with moderate sleep complaints to controls, reported that a 4month exercise intervention significantly improved subjective sleep quality, sleep-onset latency, and sleep duration.13 Vitiello et al reported an increase in slow-wave sleep in 36 exercisers but not in 21 stretching control subjects, from baseline to 6 months; however, both groups reported improved sleep quality and latency.14-16 Another study reported longer sleep duration after a 9-month moderateor light-intensity exercise intervention (N=72).17 A fifth study compared the effect of structured sleep hygiene plus moderate exercise and structured sleep hygiene plus light therapy compared to sleep hygiene alone in a small group of insomniacs (N=30, aged 18-55 years).18 Although not statistically significant, they reported increases in total sleep time using both sleepdiary data and actigraphy after 4 weeks in the group using sleep hygiene