men after 40

The Restorative Sleep Metric That Shifts After 40

After 40, sleep changes in ways that feel anything but restorative. The metric that matters most isn't how long you lie in bed, it's your sleep efficiency, the percentage of time you're actually asleep. Calculating it is simple: divide total sleep time by time in bed, then multiply by 100. Improving it requires targeted adjustments, not more hours. For deeper, science-backed strategies, our piece *Unlock Rest: Doctor-Approved Strategies for a Faster, Deeper Sleep* offers the next step toward reclaiming true rest.