Washington, June 9 (IANS) Extra sleep acts like a tonic for peak athletic performance, mood and alertness, according to new research. These findings are based on a study of five healthy members of the Stanford University men’s and women’s swimming teams.

Participants maintained their usual sleep pattern for the first fortnight. They then extended their sleep to 10 hours daily for six to seven weeks.

Extra sleep enabled athletes swim a 15-metre sprint 0.51 seconds faster, they reacted 0.15 seconds quicker off the blocks, improved turn time by 0.10 seconds and increased kick strokes by five kicks.

“These results begin to elucidate … how sleep is a significant factor in achieving peak athletic performance,” said co-author Cheri Mah of the Stanford Sleep Disorders Clinic and Research Laboratory.

The study also found that daytime sleepiness diminished significantly with extra sleep, besides improvement in mood, including higher ratings of vigour and lower ratings of fatigue.

“Typically, many athletes accumulate a large sleep debt by not obtaining their individual sleep requirement each night, which can have detrimental effects on cognitive function, mood, and reaction time,” said Mah.

“These negative effects can be minimised or eliminated by prioritising sleep in general and, more specifically, obtaining extra sleep to reduce one’s sleep debt.”

Mah and colleagues reported similar results in a previous study of six players on the Stanford men’s basketball team. Performance measures such as sprint times and free-throw shooting improved after extra sleep, as did ratings of mood and alertness. The research abstract was presented at SLEEP 2007 in Minneapolis.

“Many of the Stanford coaches are definitely more aware of the importance of sleep,” Mah said. “Coaches have even started to make changes to their practice and travelling schedules to allow for proper sleep habits, she said.

An abstract of these findings was presented on Monday at the SLEEP 2008 XXII Annual Meeting of the Associated Professional Sleep Societies (APSS) in Baltimore.