A new study finds that while both light and vigorous activity can reduce sleep disturbances, high-intensity workouts provide the greatest benefit.
Staying active is known to improve sleep, but the research findings are mixed regarding the best workout. Some studies say light walking or stretching is best, others prefer moderate-intensity workouts like jogging—and some even find that vigorous exercise such as swimming makes sleep worse.
Resolving this discrepancy is important because good sleep is known to reduce the risk of developing dementia. Many of the estimated 8 to 10 million older adults in the United States who live with mild cognitive impairment—which sometimes occurs before dementia—struggle to get a good night’s sleep. They tend to sleep about 34 minutes less per night than others, take longer to fall asleep, and spend more time awake throughout the night.
Now, researchers with the Center for Community Health and Aging at the Texas A&M University School of Public Health have a clear answer to the exercise question: Both light and vigorous exercise can reduce sleep disturbances for older adults with mild cognitive impairment.
“Most previous studies on sleep issues with this group relied on self-reported surveys, which can be problematic for participants with cognitive impairment,” says digital health care expert Jungjoo “Jay” Lee, who conducted the study along with health behavior expert Junhyoung “Paul” Kim. “We used a more objective measurement.”
For their study in the journal Digital Health, Lee and Kim used Oura Rings to measure the effects of different intensities of physical activity on sleep disturbance in seven older adults with mild cognitive impairment at a long-term care facility in the United States.
For 14 days, Lee and Kim categorized wearers’ movement as light, moderate, or vigorous based on metabolic equivalent levels and flagged restless sleep based on a specific combination of data on physical movement, heart rate spikes, and skin temperature changes. During that time, they met with participants for 15 to 20 minutes twice weekly.
“We found that high-intensity exercise is the best way to improve sleep for these older adults,” Kim says. “For every extra second of vigorous activity, sleep disruptions dropped by nearly a fifth of a second.”
Light activity also reduced sleep issues, although the impact was much smaller, and moderate exercise did not have a significant impact.
Despite several limitations in their study, including its small sample size and not breaking down the type of physical activity participants did (such as cardiovascular or strength training), Lee and Kim believe their findings fill a crucial gap.
“The number of older adults with mild cognitive impairment in the United States alone is projected to grow a whopping 76%—to more than 21 million people—by 2060,” Kim says.
“Tailored exercise programs like group walking clubs or swimming lessons could be practical, fun, and long-lasting ways for these older adults to prolong their quality of life.”
Source: Texas A&M University
