Better sleep improves physiological markers, but can it shave seconds off your giant slalom time? It seems logical to assume that better sleep equals better sports performance, but Charles H. Samuels, MD, is not one to make assumptions. As co-investigator of the University of Calgary Sports Medicine Sleep and Human Performance Research Initiative, Samuels wants to know as much as he can before he makes any conclusions.

With the recently concluded Winter Olympics in Vancouver, British Columbia, Samuels’ work got an extra dose of urgency and financial backing. With a modest $24K courtesy of Canada’s Own the Podium (OTP) initiative, Samuels became part of the government’s roughly $118 million project to enhance the performance of Canadian athletes. The New York Times called OTP a “top secret” project in which “teams of scientists have been studying the various winter sports in hope of gaining a technological edge.”

Samuels chuckles at such notions of secrecy, and while he acknowledges that athletic achievement is a focus of his work, he is interested in Canada’s summer and winter athletes beyond the realm of their events. “Yes, we want more medals, but first we want to find out if there is a global problem, and if there is, we want to develop a comprehensive strategy,” says Samuels, who also serves as medical director at Calgary’s Centre for Sleep and Human Performance. “We have a bigger responsibility, and I see sleep as a health issue. So many papers talk about sleep debt, but there is a bigger problem. There are a lot of athletes, more than we thought there should be, who are very abnormal sleepers. We want to help them.”

Five years after beginning work with athletes in a variety of disciplines, Samuels continues to study the actual extent of sleep’s effect on sports performance, while also developing ways to improve sleep for better overall health. At the request of a strength coach, Samuels began working with the Canadian National Speed Skating Team prior to the last Winter Olympics in Turin, Italy. The main concern then was the effect of international travel, but predictably sleep concerns soon expanded beyond the relatively obvious challenges of jet lag.

Teaching athletes how to manage sleep, travel, and jet lag soon grew to encompass sleep quality, circadian timing, and sleep apnea. Overall sleep quality was worse than expected among the athletes surveyed, and Canadian sports officials asked Samuels to become involved with their recovery and regeneration program. “There were big research projects funded by Gatorade looking at hydration status for recovery, but little work had been done in sleep,” says Samuels, who spent the first few days of this year’s Olympics with the Canadian cycling team at a training camp in Tucson, Ariz, and will be heading to Phoenix in late March to work with the track team in preparation for the summer season and the upcoming London Olympics. “Coaches, trainers, and sports medicine docs all believe that sleep is a huge issue in athletes. I have always remained a skeptic saying, ‘Well, prove it.’ They were so adamant that I agreed to get involved, and that was 5 years ago now.”

A 2-year project to develop an athlete sleep screening questionnaire is nearly complete after screening more than 300 national Winter Olympic team members. Validating and verifying the reliability of the test is no small chore if it is to have actual scientific value. “Doing athlete research is like herding cats, because they are constantly on the move,” says Samuels. “I am a population researcher, so I’m interested in the bigger issues of the population itself. All the work to date has focused on sleep debt in athletes and the performance consequences. This is important work, but I’m more interested in these athletes as a group of people.”

Research shows that people who exercise usually sleep better, but increasingly that is not the case with extreme exertion in elite athletes. Elements such as pressure and adrenaline play heretofore unknown roles, and that makes sound research all the tougher. “These are elite athletes who train rigorously, and it’s clear that their sleep patterns change through the cycle of their training, which is termed periodization,” explains Samuels. “Setting aside travel, there are so many factors that affect sleep, and we are now starting to drill down into finding out what we need to understand. But without first determining the prevalence of problems within the population, you are just chasing a dream. First and foremost, you want to know: Is there even a problem?”

REST AND RECOVERY

Coaches have long implored athletes to heed curfews, and anecdotal evidence shows that better sleep sharpens athletic performance. Samuels and his colleagues are working to get beyond the anecdotes, because the need for strong science is greater than ever. About a third of Canadian athletes surveyed are scoring in the so-called red zone of abnormal sleep, and whether you are skiing, curling, skating, or just driving to the practice facility, that is a problematic statistic.

When it comes to training for an athletic event, sleep regimens become part of the periodization strategy. The cycles of training—and recovery through sleep—ultimately depend on the sport. “First determine whether it is a power sport or an endurance sport,” says Samuels. “Then break it down into volume, intensity, and frequency of training. Training a power athlete is a lot different than training an endurance athlete. An endurance athlete is going to have a much higher volume of training for the sheer purpose of cardiovascular efficiency. Both have different recovery needs through sleep.”

Sleep and training take up most of an athlete’s time, at least those who are fortunate enough to get funded by government entities. Samuels uses the example of swimming, a sport that has cultivated a long tradition of brutal training schedules, to illustrate the challenges of getting the proper sleep. “Elite swimmers start when they are young, and meet their competitive peak in their twenties,” says Samuels. “At the time when they really need to be getting the most sleep in their life, they are waking up at 5 in the morning to go to the pool and train from 6 to 8 so they can get to school by 9. Very talented athletes often can’t make it through this schedule. They just run out of gas.”

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Samuels agrees that sleep is the foundation of recovery, and all other aspects of recovery revolve around that. If athletes are not devoting enough time to sleep, their ability to maximize recovery suffers, and performance soon follows.

Genetics plays a role and must be considered when creating any sleep program. Some people need less sleep and some need more. “Some sleep programs apply to all athletes, while others require individualized regimens. We see that spectrum as we drill down into the data and look at the total sleep needs of each athlete. We are in the process of analyzing that data just to look at the spread. We are seeing the range based on self-reported numbers and not objective measures.”

Physicians involved with the Canadian Alpine Ski Team value sleep enough to include an expert such as Samuels on their integrated support team among sports scientists, physiologists, and other doctors. They sat down with Samuels and said, “We have a huge problem in alpine with injury prevention related to anterior cruciate ligament tears. We believe sleep plays a huge role, because being tired is the number one complaint that leads a skier at high speed to screw up. We want you to help us with the fatigue factor related to sleep.”

Injury prevention through sleep may be a relatively new concept for sports, but in industries such as trucking, reducing sleep apnea is now considered a matter of public safety. For sliders in the bobsled, skeleton, and luge, split seconds make a difference. In these events, focus is absolutely critical, but endurance is not as important.

CLINICAL CONSIDERATIONS

Samuels has written that although a complete understanding of the function of sleep in humans remains unknown, certain indisputable facts remain: 1) sleep restriction (sleep deprivation) is linked causally to cognitive impairment; 2) there is interindividual variability in the response to sleep deprivation with respect to the degree of cognitive impairment; and 3) critical metabolic, immunologic, and restorative physiologic processes are negatively affected by sleep restriction, sleep disturbance, and forced desynchrony of the human circadian sleep/wake phase.

If Samuels deemed it necessary to give an athlete a sleeping pill to deal with these issues, such a medication would certainly not be a banned substance under international rules, since sedatives are a performance inhibitor in virtually all sports. Samuels routinely prescribes melatonin for jet lag and other conditions, which is also not banned. For athletes who were drowsy, stimulants would be a definite no-no—with the exception of caffeine.

As to sleep’s impact on glucose metabolism and cortisol (a corticosteroid hormone sometimes referred to as the stress hormone), Samuels sees some misconceptions about the relevance to elite athletes. “Everyone seems to focus on cortisol, and as doctors we usually see an extremely simplistic view,” says Samuels. “Metabolism is critical, so it is important to understand that sleep is the period of recovery physiologically from a cognitive, neurological, and metabolic standpoint. Glucose utilization, tissue regeneration, and protein uptake are all factors that come under metabolic recovery, and then tissue recovery. Athletes are tearing down tissue for a reason. The whole point of training is to subtly overreach an athlete to gain better strength and performance. That is actually the strategy around periodization.”

Essentially, there should be a period of peak training that actually overreaches the athlete, from which they should recover within 48 hours. “The key thing here is that we now know that sleep is an important human physiological state, during which recovery occurs across those domains,” explains Samuels. “We believe that dream sleep or REM sleep is a state where memory and tasks are learned and consolidated. If you are teaching a tennis player a new serve, or correcting some kind of imperfection in a speed skater’s start or turn, you want them to imprint that learning process. Sleep is a time when part of that imprinting goes on cognitively.

“The other thing is that we know that alertness, cognition, and attention are significantly affected by reduced total sleep time,” adds Samuels. “So if you reduce a person’s sleep time, their ability to attend to a task will decline. This is certainly not a good thing in high performance sports.”


Greg Thompson is a contributing writer for Sleep Review. The author can be reached at sleepreviewmag@allied360.com.

Most for the Host?

Previous attempts at Montreal (1976 Summer Games) and Calgary (1988 Winter Games) failed to yield gold medals for Canadian athletes. This time around in Vancouver, America’s friends to the north used government money and cutting edge medical science to turn around those results. The jinx has not extended to other countries such as Italy where Canada earned seven gold medals (24 total medals) in the 2006 Turin games.

Canada’s athletes did well on World Cup circuits in pre-Olympic events, and expectations were high. According to Samuels, odds makers projected Canada to be the biggest medal takers. Canada led the 2010 Winter Games gold medal count with 14. In total, Canada earned 26 medals, Germany walked away with 30, and the United States won 37.