A new study has ranked the best types of exercise for improving sleep quality. The findings demonstrate that exercise is an easy-to-implement, relatively cheap, and particularly effective way of treating insomnia, a common problem for older adults.
Insomnia is a problem commonly associated with aging, with as many as 50% of older adults reporting difficulty initiating or maintaining sleep. Insomnia’s effects are bad enough to it warrant being listed as a sleep disorder in the psychiatrist’s ‘bible,’ the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). And plenty of studies link a lack of sleep to health issues.
While cognitive behavioral therapy (CBT-I) is the first-line treatment for insomnia, it can be time-consuming, costly, and difficult to find qualified therapists. As an alternative to CBT-I, a new study by researchers from Mahidol University’s Faculty of Medicine Ramathibodi Hospital, Thailand, has examined exercise’s impact on sleep quality.
The study was a systematic review and meta-analysis of 25 randomized controlled trials conducted between 1996 and 2021, encompassing 2,170 participants. It evaluated and compared the impact of different types of physical exercise on sleep quality in adults aged 60 and older. Participants were included if they had been diagnosed with insomnia according to DSM-5 criteria.
The Global Pittsburgh Sleep Quality Index (GPSQI) was used to measure sleep quality outcomes. The Pittsburgh Sleep Quality Index (PSQI), from which the GPSQI is derived, consists of 19 self-rated questions about seven components, including sleep quality, duration, how long it takes to fall asleep, how much time is spent in bed actually sleeping, sleep disturbances, use of sleeping medication, and degree of daytime dysfunction. With the PSQI, each of these individual components is scored and provides a total score that ranges from zero to 21, with a lower score indicating better sleep quality. Instead of analyzing individual component scores, the GPSQI combines all seven components into a single overall score for easier comparison in studies.
Eighty percent of the reviewed studies were conducted in community settings, and 20% were carried out in nursing homes. In more than half (54.55%) of the studies, exercise intensity was mild to moderate. The average workout time per session was around 54 minutes, and the number of sessions per week was three in 48% of studies and twice weekly in 35%. The baseline GPSQI scores between exercise and control groups were 8.37 and 8.27, respectively.
Overall, the researchers found that GPSQI scores dropped, suggesting that people slept better when they exercised. But some types of exercise produced better results than others. Those who did aerobic exercise like running, cycling, or swimming saw a GPSQI drop of 4.36 points, meaning significantly better sleep. However, the variation between results suggested that different studies had produced quite mixed results, so while the effect of aerobic exercise on sleep quality is strong, it wasn’t super consistent across all trials.
The exercise type that produced the best effect on sleep quality was strength or resistance training. This includes using free weights, weight machines or resistance bands. In the network meta-analysis (NMA), strength/resistance training lowered GPSQI by 5.75 points. Whereas standard meta-analysis only lets researchers compare things head-to-head (for example, aerobic exercise versus no exercise), NMA lets them compare multiple treatments at the same time, even if they weren’t directly compared in the same trials. Basically, it allows researchers to connect the dots between different studies and estimate which treatment is the absolute best. (By the way, network meta-analysis also found that combination exercise improved sleep, but it only dropped GPSQI score by 2.54 points.)
“This study shows that exercise, particularly strengthening exercise and aerobic exercise, is beneficial for enhancing subjective sleep quality at a clinically significant level compared with normal activities, which is consistent with previous studies,” the researchers said. “Strengthening has the highest efficacy, followed by aerobic exercise and combination exercise. Nevertheless, caution should be applied when interpreting this study because of the diverse exercise characteristics, the small number of studies, and the high risk of bias among studies.”
The researchers know that not all types of exercise are appropriate for everyone.
“Some exercises may be challenging for older people because of complicated techniques, restricted physical capabilities, and the requirement for an experienced instructor,” they said.
The important take-home message is that all the forms of exercise they examined improved sleep quality to some degree. So, someone unable to do strength training can still benefit from another kind of exercise.
Future research could incorporate both subjective and objective measures, such as heart rate and oxygen consumption, to validate the effect of exercise on sleep.
The study was published in the journal Family Medicine and Community Health
