NFL athletes are on a tight routine to get their bodies ready for Sunday.

Training. Diet. Recovery techniques. Flexibility. Each are measured to the exact minute or gram for maximum performance.

But ask any mother of a 6-month-old and she’ll tell you what the No. 1 ingredient in a productive day is.

Sleep.

And science agrees.

According to Jenny Vrentas of Monday Morning Quarterback, a good night’s sleep is directly tied to an athlete’s ability to manage reaction time, mental alertness, muscular recovery and memory.

“That’s why the science of slumber has become one of the hottest trends in the NFL,” Vrentas writes. “Teams are no longer leaving it to chance that their multimillion dollar investments will manage sleep cycles all on their own.”

The Miami Dolphins and New England Patriots provide dark rooms at practice facility for naps. The Philadelphia Eagles have players report how long and how well they sleep each night. The New York Jets use Litebook for early morning and late night film room sessions to provide the glow of natural daylight.

SEE ALSO: Sleep, nutrition and stretching are key components to preseason training

According to the Harvard Business Review, living consistently on four hours of sleep each night is like drinking a six pack of beer before work every day. An 80-hour work week was once the norm in both the corporate world and the sports world. No more.

“Encouraging a culture of sleepless machismo is worse than nonsensical; it is downright dangerous, and the antithesis of intelligent management,” Dr. Charles A Czeisler of Harvard Medical School told the Harvard Business Review.

The consistent lack of sleep can put people on the brink of self-destruction, potentially leading to exhaustion, poor performance and bad decision-making.

“The average athlete probably needs eight to nine hours of sleep, given their physical demands,” Czeisler told MMQB. “I wish I could say there’s a shortcut, but if you are going to be a professional athlete, you need to pay careful attention to sleep.”

This is an important lesson not only for NFL coaches and players but those at the college and high school levels as well. Pushing your body beyond its limits to meet the stresses of the job is more detrimental than calling it a night and coming back fresh.

And it works.

According to MMQB:

• Patriots quarterback Tom Brady targets 9 p.m. as his bed time on non-game nights
• Houston Texans defensive end J.J. Watt on HBO’s “Hard Knocks” talked about getting to sleep by 8:30 p.m. most nights.
• Indianapolis Colts kicker Adam Vinatieri credits his continued excellence on getting at least eight hours of quality sleep each night.

“(At first) I thought it was odd,” Jets quarterback Ryan Fitzpatrick told MMQB. “It was out of the norm and not something I had ever done before. But even if it was going to help just a little bit, why not try it?”