The All-Star point guard Steve Nash is 37 and knows that decline may come fast at his age. But his solution is not to increase his conditioning or to lift more weights. Instead, he plans to increase his naptime, seizing on an element of N.B.A. life as common as a 3-point shot.

If you nap every game day, all those hours add up and it allows you to get through the season better,” Nash said. “I want to improve at that, so by the end of the year, I feel better.”

Nash is among a great majority of N.B.A. players who swear by their pregame nap. Most are interested in its restorative benefits, although a few may just be trying to counter boredom. Whatever the reason, balls stop bouncing and shoes stop screeching every afternoon.

“Everyone in the league office knows not to call players at 3 p.m.,” said Adam Silver, the league’s deputy commissioner. “It’s the player nap.”

In the United States, napping is often stigmatized, seen as evidence of laziness or a lack of purpose. But in the world of sports, and certainly in the N.B.A., the attitude is entirely different.

“You’re nocturnal in terms of what you do, playing at night, so your body adjusts to the rhythm of being up late, getting in early in the morning,” said Grant Hill, Nash’s teammate with the Phoenix Suns. “You’re tired around midday. Naps are important. It refreshes you. It gets you ready for competition.”...