411. Dropping Science: Naps

For More Endurance Noise & Random Musings! How to harness the power of the midafternoon nap Suspend your skepticism for a moment, and imagine a powerful new performance aid that boosts your physical power, improves your reaction time and decision-making, and protects you against oxidative stress and muscle damage. On the surface, the results were fairly straightforward: A night of short sleep hurt all the performance and health measurements, and an afternoon nap partly or fully restored them. That’s what you’d expect based on previous research – but there are some interesting new wrinkles, according to Anthony Blanchfield, a psychophysiologist at Bangor University in Britain, who has studied napping in athletes and was not involved in the Tunisian study. “The finding that napping in athletes can specifically attenuate some of the markers that are linked to oxidative damage and muscle damage is novel,” Over the past few decades, sleep researchers have accumulated evidence that getting less sleep than you need has effects throughout the body, pumping up stress hormones, suppressing immune function, and promoting systemic inflammation that raises the risk of cardiovascular disease and diabetes. But whether a brief afternoon nap is enough to reverse these negative effects remains unclear. One key aspect of the Tunisian study is that the naps came after a night of partial sleep deprivation. That might be applicable if, for example, you’ve had a restless night before a big competition, but it’s less clear that the nap would have similar benefits after a normal night of sleep. In a 2018 study led by Blanchfield and his colleague Sam Oliver, runners completed a pair of time-to-exhaustion tests on a treadmill, once with a 40-minute nap opportunity finishing 90 minutes beforehand, and once without. The overall results showed no performance benefit from napping. But a closer look found that the runners who improved with a nap had averaged 6.4 hours of sleep the night before, while those who saw no improvement had averaged 7.5 hours. “It seems likely that a nap is most effective when an athlete encounters some form of sleep disruption the night before exercise,” Blanchfield says, “or in those sports where early morning training is standard practice – for instance, swimming.” That’s why Charles Samuels, the head of the Centre for Sleep and Human Performance in Calgary, typically recommends limiting naps to between 15 and 30 minutes unless you’re trying to make up for an acute bout of missed sleep or travel fatigue. At a conference for Canadian Olympic team staff last fall, he suggested having a coffee before starting this kind of ultrabrief nap, to help kick-start your alertness when you wake up. And if the logistics of such a short nap seem daunting, Samuels had some reassuring words. “When I say nap, I mean lying down, eyes closed, deep breathing,” he said. “I couldn’t care less if you sleep. This is about brain rest.” https://www.theglobeandmail.com/life/health-and-fitness/article-how-to-harness-the-awesome-power-of-the-midafternoon-nap/