The Importance of Sleep for the Triathlete.
Sleep is important to maintain good overall health for optimal physical and mental performance. Sleep affects physical health, emotional well-being, mental sharpness, productivity and athletic performance. Studies associate lack of sleep with serious health problems such as an increased risk of depression, obesity, cardiovascular disease and diabetes. Quality of sleep is just as important as quantity. If your sleep is frequently interrupted, you will not achieve quality sleep, which will affect your performance as a triathlete.
The correlation behind sleep and performance is an important factor for triathletes, and many performers underestimate this key principle. It’s well documented that 7 to 9 hours sleep is the daily norm to function physiologically and psychologically in a homostatic manner, why is this the case? What happens to the triathlete’s performance if we don’t get enough sleep? Do hormones play a vital part in the sleep/triathlon/competition cycle whilst we are asleep? Is resting the same as sleeping for the triathlete?
Prior to understanding how sleep can affect the triathlete’s performance; we must get to grips with the fundamental characteristics of sleep and understand the close relationship it has with this performance process. While no one completely understands the integral mechanics of sleep, it’s clear that there’ re five key phases of the sleep cycle. Each of the five phases has its own unique characteristics and can last from between 90-120 minutes, with the brain having different signals/electrical patterns during each phase. These phases can be summarised as follows;
Stage One (light sleep)
This involves the eye function and body movement slowing down. Muscles start to twitch (myoclonia jerks) and you get the feeling that you are falling. You are floating in and out of sleep.
During this part of sleep your eyes stop moving and brain waves slow down. Brief, rapid bursts of brain waves occur called brain spindles
Stage Three (the first deep sleep phase)
The brain is making slower and faster delta waves, it’s difficult to wake a person up in this phase. If you do wake up the person, they will be disorientated and take time too come around. Growth hormone is secreted during this short wave stage
Stage Four (the second deep sleep phase).
The brain is making the exclusively slower delta waves and this phase is called the second dream phase. It’s paramount to feeling refreshed. Growth hormone is likewise secreted during this vital stage of the sleep cycle.
Rapid Eye Movement (R.E.M) is probably the most infamous stage of sleep R.E.M should be at least 20% of the total amount of a healthy sleeping pattern. Certain physiological processes happen during R.E.M such as your heart rate, blood pressure and breathing rate all increase with your eye movement becoming more rapid and your muscles being immobile. Researcher’s have discovered that the R.E.M stage is important in the creation of long-term memories. If a person’s REM sleep is disrupted, the next sleep cycle does not follow the normal order, but often goes directly to REM sleep until the previous night’s lost REM time is made up.
Sleep researchers are discovering that sleep deprivation can have a massive impact on our basal metabolic rate and not getting adequate sleep can reduce glucose metabolism by as much as 40%. Human grow hormones is attenuated during sleep debt, this has a main function in tissue growth and HGH is very important in the triathlete’s recovery process.
Levels of cortisol (a stress hormone) is higher during sleep deprivation periods, which has been linked to memory impairment, age-related insulin resistance and impaired recovery in athletes. Studies of sleep deprivation and athletic performance has indicated that there is a link between aerobic endurance and increased rating of perceived exertion, thus if you are in sleep debt the physical task seems more arduous. Elevated levels of cortisol may interfere with tissue repair and growth. Over time, this could prevent a triathlete from responding to heavy training and lead to over training and injury.
Glucose and glycogen (stored glucose) are the main sources of energy for triathletes. Being able to store glucose in muscle and the liver is particularly important for endurance athletes. Those who are sleep deprived may experience slower storage of glycogen, which prevents storage of the fuel an athlete needs for endurance events beyond 90 minutes, which is absolutely critical for the triathlete. For the endurance athlete, adequate sleep during heavy training and before competitions certainly would help and have an impact on your personal best.
Do naps count?
Many of us wonder about naps. While a “power nap” may seem like a great idea at times, naps do have a downside. Upon awakening, people often manifest performance deficits and are foggy and clumsy. This effect intensifies with progressive sleep loss, especially at night. Very short naps (of about ten minutes) may offer some recuperative benefit when people are sleep deprived without producing noticeable levels of performance deficits.
The Importance of Sleep for Triathletes.
Extra sleep could potentially help you shave seconds or even minutes off your race finishing time. So how much sleep should you need for optimum triathlon performance?
Every individual has different sleep requirements, and different factors such as stress can all play a part in how much sleep a person needs. What is without doubt is the fact that an increased training load requires more sleep so that their body can recover sufficiently. The elite triathlete will require more sleep than a beginner; because they are likely to be putting more demands on their body through their advanced training schedule.
Monitoring your Sleep Requirements
How do you know when you’ve had enough sleep? The ideal answer is to sleep until you wake naturally, rather than try to set a rigid nightly figure. For most people with commitments, this approach is not really a practical option. Instead, start a sleep chart on which you record the time you go to bed, the time you wake up, how long you slept, whether your sleep was broken, how quickly you think you fell asleep, and how refreshed you felt when you woke in the morning.
Compare your sleep patterns with your training schedule, and over a period of weeks you should be able to see a pattern emerging. Complete this data daily and over a typical representative period of several weeks. Compare when you’ve slept well and felt refreshed with periods when your sleep hasn’t been great or you’ve felt a bit groggy on waking.
Sleep and the Elite Triathletes
Many elite athletes sleep for around nine hours each night, supplemented by a further two hours in the afternoon. This sleeping strategy is aimed at rebuilding stressed and damaged muscles faster. In addition to getting a good night’s and afternoon’s sleep, it is also known that human growth hormone is secreted during phases 3 & 4 of sleep. By sleeping twice a day, you get a double hit off the hormone, which accelerates your recovery.
A regular diet of good quality sleep will support your body and mind during your actual training, but a sleepless night before race doesn’t mean that your chances of a good race or a PB have disappeared. Getting your full quota of sleep in the days coming up to the race is vitally important, even if the night before the race you struggle to sleep well.
Training volume and intensity, nutrition, stress, domestic and work responsibilities, personality, race conditions, mood, motivation and a host of other factors all play their part in affecting your performance, so it is difficult to measure sleep against performance. However, clearly achieving a PB on a one hour of sleep each night simply isn’t going to happen, so sleep will be a key factor. Only through experience of numerous races will you be able to build up a picture of how much sleep has an impact on your own performance.