Regeneration: Sleep, probably the most effective & yet most underestimated medicine

"The Tour is won in bed" was a motto that Tour de France winner and road world champion Joop Zoetemelk adopted back in the 1980s. Today, sleep is an integral part of the training and competition schedule of most professional teams: Team Visma, for example, travels to the race with its own pillows and mattresses so that the riders can sleep as usual.

Luke Durbridge, pro with Team Jayco AlUla, wears glasses with a blue light filter and takes melatonin to ensure a good night's sleep during the Tour of France. Canadian Nathan Pruner from Team TaG Cycling relies on a cool bedroom for a good night's sleep, puts his mobile phone away an hour before going to bed and drinks a glass of water. During the Tour de France 2025, Team Cofidis used a smart ring that the cyclists wore on their fingers to track their recovery and sleep.

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The situation is quite different for many amateur athletes: Sleep is often the first thing they skimp on in order to fit in their training schedule alongside work and other private commitments. However, this doesn't mean they gain time, but lose performance, because: "Sleep is important for endurance athletes, among other things, so that the muscles can regenerate," explains Kneginja Richter, sleep physician, head physician at the Curamed day clinic in Nuremberg and professor at Nuremberg Institute of Technology.

Shutting down in deep sleep

So if you want to perform at your best or for the long term, you need to get enough restful sleep. The fact that sleep plays a decisive role in regeneration is due, among other things, to hormonal processes that take place during rest and, it is assumed, also to the altered brain frequency, which has an influence on physical recovery processes: "Muscle and tissue recovery is linked to the delta brain waves. These are the slowest electrical signals in the brain that are active during deep sleep," explains sleep expert Richter.

During physical rest, the brain primarily processes information and controls various regenerative processes in the body. In the deep sleep phase, for example, it tells the organism to release more growth hormone, testosterone and IGF-1 - all of which are messenger substances that are important for protein synthesis, i.e. for muscle recovery and development. And they react sensitively to sleep deprivation: "Just one sleepless night can reduce the total testosterone level in the blood by almost a quarter," explains sleep physician Kneginja Richter.

Training with eyes closed

To enter the deep sleep phase, we must first go through the falling asleep and light sleep phases, in which muscle tension is reduced, eye activity stops and the body "shuts down" overall. This phase makes up about half of the sleep cycle.

This is followed by the aforementioned deep sleep phase of around 20 per cent, during which the body switches to regeneration and it is difficult to wake up. Dream or REM sleep also accounts for around 20 per cent. This is the final phase of the sleep cycle, during which the eyes move, we dream and information is transferred from short to long-term memory.

An adult goes through three to five of these cycles per night, with the deep sleep phase becoming shorter and shorter over the course of the night or being cancelled completely. If we sleep too little overall, there is a risk that the body will not spend enough time in deep sleep to recover sufficiently.

Tips: What makes sleep better ...

• Regular times for getting up and going to bed
• dark, cool bedroom (16-19 °C)
• No more caffeine from the early afternoon, moderate/no alcohol consumption
• Warm shower one to two hours before going to bed
• Meditate, relaxation techniques

... and what not necessarily

• Blue light filter glasses
• Dimming mode for screens
• Sleep teas, valerian, lavender or camomile

Factors such as shift work, diet (lots of fast food, sugary foods, caffeine and alcohol) or stress can also disrupt sleep and therefore also deep sleep. "If the deep sleep phase is interrupted, you are not rested," confirms sleep physician Richter. And this lack of rest slows down or disrupts various regeneration processes.

Do not disturb!

Those who cut back on their sleep, for example, disrupt the anabolic and catabolic processes in the body, i.e. the build-up and breakdown of structures such as muscles. Studies show that a lack of sleep leads to a maladjustment of the circadian rhythm, which controls the sleep-wake cycle. This in turn impairs the metabolic processes in the muscles and liver.

Even single nights of severely reduced sleep can reduce muscle protein synthesis, destabilise the metabolism and create a hormonal environment that promotes muscle breakdown. At the same time, cortisol levels rise - a classic stress hormone that accelerates catabolic, i.e. catabolic, processes.

The organism can compensate for the odd restless night within a few days, but repeated sleep deprivation over weeks or months causes performance and muscles to deteriorate. Those who constantly carry a sleep deficit around with them also increase the likelihood of inflammatory processes in the body.

For example, three nights of reduced sleep increase the concentration of certain inflammatory markers in the blood, including interleukins and chemokines, both of which are involved in the body's immune defence. If the body's defences are weak and unable to curb the inflammation, it can become chronic and damage the tissue. In combination with intensive training in particular, this condition acts as an amplifier for muscular fatigue, reduced adaptability and delayed regeneration.

Too little sleep can make you ill

While sleeping poorly from time to time is neither a cause for concern nor an immediate performance killer, a sleep disorder should be checked out by a doctor. Sleep disorders do not appear to be that rare among cyclists: 41 per cent of the 112 elite riders who took part in a study conducted in 2024 had poor sleep quality.

According to Kneginja Richter, sleep disorders, including the most common form of insomnia, can often be attributed to a constant state of arousal caused by physical exertion and a lack of relaxation in endurance athletes.

If you permanently cut back on sleep and rest periods in order to be able to cycle more, you are not only training yourself into a regeneration and performance hole, but perhaps also into pathological insomnia. This occurs when someone has a problem sleeping through the night more than three nights a week for three months or needs longer than 30 minutes to fall asleep.

Sleep disorders in endurance athletes are often due to a constant state of arousal caused by physical exertion and a lack of relaxation. - Kneginja Richter, sleep physician, head physician at the Curamed day clinic in Nuremberg

Anyone who generally sleeps well but wants to fall asleep and stay asleep even better - after all, seven to nine hours of sleep per night is considered ideal - can improve their night's rest with a few simple measures. "Sleep hygiene" is the name of the setting that sets the course for reliably peaceful slumber.

"It's important to wind down two hours before going to bed," advises Kneginja Richter. This is roughly when the level of the sleep hormone melatonin rises. So that it can do its job, bright light and mobile phone, computer or tablet displays should be switched off. Both slow down melatonin production.

It also makes sense to avoid sleep-killers such as caffeine and alcohol from the afternoon onwards, while foods such as kiwi, cherry juice or dairy products can have a sleep-promoting effect due to certain ingredients.

The bedroom should be dark, quiet and cool (between 16 and 19 degrees Celsius) and your mind should be at ease: "Go to bed with pleasant thoughts. For this to work, it can help to consciously take 20 minutes every day to think about worst-case scenarios and fears. Then they will torment you less at night," recommends sleep expert Richter.

She has also had good experiences with meditation (at best several times a day) with regard to restful sleep. On the other hand, blue light filter glasses and the "dimming mode" on screens have no clear scientific benefit. As is so often the case, however, the same applies here: What works for whom varies from person to person. Try out what brings you down and does you good.

Better performance for free

"Good sleep doesn't cost money," summarises Kneginja Richter. But it is valuable. Because it is probably the most effective and at the same time most underestimated regeneration factor.

It is therefore worth learning good sleeping habits without driving yourself crazy if one night is more restless or slavishly tracking the quality of sleep: "Regardless of whether I have slept four, six or eight hours, if I feel awake when I get up, I have slept enough," says the sleep doctor, formulating a simple rule of thumb.

And getting a good night's sleep is probably just as important for cyclists in terms of performance as a cleverly structured training plan.