The Science of the Power Nap: What NASA's Research Found

Kim Berglin

Sep 4

2 min read

A look at the research behind the so-called NASA nap, and why a shorter nap can leave someone more alert than a longer one.

A 26-Minute Nap Outperformed a Longer Opportunity

A 1995 NASA study gave pilots up to 40 minutes to nap, and later analysis of the results pointed to roughly 26 minutes as the most effective duration, according to Sleep Foundation. Pilots who took that nap showed a 34% increase in job performance and a 54% increase in alertness compared with pilots who skipped the nap entirely.

Sleepiness Stayed Lower for the Rest of the Shift

Napping pilots also reported less sleepiness toward the end of their flights, while non-napping pilots showed twice as much sleepiness by comparison. Benefits from a well-timed short nap extended well past the nap itself, carrying into the hours that followed rather than fading immediately.

Sleep Inertia Explains Why Longer Isn't Better

Naps stretching past 30 minutes raise the odds of waking into sleep inertia, described as a dazed, sluggish feeling that can undercut whatever alertness the nap was meant to provide. Keeping a nap under half an hour is the practical guardrail that keeps this grogginess from canceling out the benefit.

A Short Nap Fits Naturally Into a Workday Reset

Setting an alarm for 20 to 26 minutes, rather than lying down without a plan, is the simplest way to capture the alertness gain without drifting into deeper sleep stages that trigger inertia. Treating a nap as a scheduled, time-boxed reset rather than an open-ended rest works with how the research measured its benefits in the first place.

Bottom Line

A short, deliberately timed nap delivers a meaningful alertness and performance boost without the grogginess that comes with sleeping too long. Setting a firm 20-to-26-minute window turns napping into a targeted tool rather than a gamble on how the rest of the day will feel.

Our piece on micro-recovery and rest during the workday covers other short reset habits that work alongside a well-timed nap.