Lifting weights beats cardio for sleep in older insomniacs

Insomnia becomes more common with age, and exercise is one of the few remedies that is free, safe for most people and comes without a prescription. But exercise is not one thing. Aerobic activity, strength work and combined routines place very different demands on the body, and until now nobody had systematically ranked them against each other for sleep in older people with insomnia. Knowing which type helps most matters, because an older adult with limited time and energy has to choose something.

The researchers swept six databases from their inception to October 2022 for randomised controlled trials comparing physical exercise against routine activities, usual care, non-physical activity or health education in older people with insomnia. Sleep quality was measured with the Pittsburgh Sleep Quality Index. Twenty-five trials covering 2170 people qualified. Direct comparisons were pooled first, then a network meta-analysis ranked the exercise types against one another, including comparisons that no single trial had made directly.

In direct comparisons, combined exercise improved the global sleep quality score by 2.35 points and aerobic activity by 4.36 points, though the aerobic trials disagreed with each other considerably. In the network analysis, strengthening, aerobic and combined exercise all significantly lowered the global score, by 5.75, 3.76 and 2.54 points respectively. Strength training came out on top of the ranking, with a 94.6% score on the method used to order treatments. The authors conclude that muscle-strengthening exercise is the most effective type for enhancing sleep quality.

Most exercise-and-sleep advice has historically leaned on walking and other aerobic activity, so a ranking that puts strength work first is a genuine shift in emphasis. It fits a broader pattern of resistance training earning benefits well beyond muscle. The caution is that network rankings rest partly on indirect comparisons, and the included trials varied a great deal, so the ordering is a best estimate rather than a verdict. How much strength work, at what intensity and for how long remain open questions.

If you or an older relative struggles with sleep, this is a reason to think resistance exercise counts towards fixing it, perhaps more than a walk does. It also suggests that any of the three exercise types beats doing nothing, since all significantly improved sleep quality scores. The finding applies to older adults with insomnia, so younger or well-sleeping readers should hold the conclusion more loosely.