In the most recent ESPN- The Magazine,  Peter Keating highlights a study on sleep by Stanford researcher Cheri Mah, who explored the question, does extra sleep boost athletic achievement?

Over three seasons, from 2005 to 2008, the scientists looked at 11 Stanford basketball players.  For two to four weeks, the Cardinal kept to their normal schedules.  Then for five to seven weeks, they watched what they drank, took daytime naps and tried to sleep for 10 hours every night.  After increasing their daily rest, the players sprinted faster and said they felt better in practices and games.  Their aim got better too: Their three-point shooting humped 9.2 percentage points, and their free throw percentage increased by nine points.

What is responsible for this improved performance?  According to Keating:

Some of our genes act as internal clocks and release hormones according to cycles called circadian rhythms, which are triggered by darkness and light and alternate over 24-hour periods.  When we mess with these rhythms by not getting enough sleep, our metabolism of glucose (which gives us energy) declines, and our level of cortisol (which causes stress) increases.  Further, sleeping for longer stretches is naturally anabolic: During deep sleep, our bodies release growth hormone, which stimulates the healing and growth of muscle and bone.  So while it's possible to push through a lack of sleep during any one day, proper sleep helps athletes in two ways.  First, it boosts areas of performance that require top-notch cognitive function, like reaction time and hand-eye coordination.  Second, it aids recovery from tough games and workouts.

 HR professionals could glean a couple of insights from this study.  First, despite our best laid plans, our training, incentives, and motivation will likely have muted impact if employees are coming in tired.   Further, instead of stocking our refrigerators with Mountain Dew and 5 Hour Energy Drink, and keeping the coffee pot brewing, we would be better off setting up a number of nap rooms.