Getting enough sleep each night boosts performance in the saddle by an average of two minutes over the course of cycling time trials that typically take 60 minutes to complete, Deakin University researchers have found.
The research could make a critical difference for professional-level cyclists such as those competing in the Tour de France, where in last year's race just one minute and 51 seconds separated first and second place.
Spencer Roberts, a PhD candidate within Deakin's School of Exercise and Nutrition Sciences, said tests show endurance cyclists complete time-trials, on average, two minutes faster after getting an extra 90 minutes sleep per night for three consecutive nights.
The 'Extended Sleep Maintains Endurance Performance Better than Normal or Restricted Sleep' study, published in the latest edition of Medicine & Science in Sports & Exercise, is the first ever study to test the influence of sleep extension on the performance of endurance athletes.
The researchers put nine competitive endurance cyclists and triathletes through a series of endurance tests while manipulating their nightly amount of sleep. First, they pedalled 60-minute time trials over four consecutive days while getting their normal amount of sleep each night - approximately seven hours per night.
The cyclists then completed the same time trials over another four-day period, but this time spent more time in bed, sleeping approximately 8.5 hours each night. Finally, the researchers repeated the testing a third time while reducing their time in bed, leaving them with just under five hours of sleep each night.
The cyclists were considerably slower after just two nights of sleep restriction, completing their time trial in an average of 60.4 minutes, compared to 58.8 minutes, when they had had five hours of sleep - a three per cent decline in performance.
The athletes' performance significantly improved following three nights of extra sleep, finishing their time trial an average of nearly two minutes faster (58.7 minutes versus 56.8 minutes) when they had 8.5 hours sleep - a three per cent improvement in performance.
The cyclists reported the same rating of perceived exertion - the time trial felt just as hard - regardless of their sleep status. However, Mr Roberts said their mood and "psycho-motor vigilance", or sustained attention and reaction time, both improved with more sleep and were hindered by sleep restriction.
Mr Roberts said competitions like the Tour de France highlighted the need for elite competitors to know the science behind gaining an edge.
"Getting a good night's sleep could be the missing piece of the puzzle to success,"Mr Roberts said. "And for riders on the Tour, getting a good night's sleep could potentially be the one or two minutes difference to wearing the yellow jersey."
Mr Roberts said a couple of studies have examined the benefits of regularly getting more sleep on ball and skill sports like football, basketball and tennis, but this is the first study to put endurance athletes to the sleep test.
The Deakin research team included PhD Candidate Spencer Roberts, Dr Weipeng Teo, Professor Brad Aisbett and Dr Stuart Warmington.
