Athletic Recovery

Sleep quality and duration have lately been recognized by professional athletes and their medical teams as one the most important factors in athletic performance and recovery. Many professional sports teams have employed sleep specialists to help their athletes with sleep issues as well as circadian rhythms disruption. Circadian rhythms disruptions include poor sleep quality, lack of adequate sleep in anticipation of an upcoming competition, and even jet lag when traveling across several time zones.

As sleep disorders are common among athletes, it is extremely important to educate athletes about the pivotal role that adequate, well-regulated and timely sleep plays on performance and recovery. Balanced and entrained circadian rhythms play an extremely important role in athletic training, performance, and recovery.

Together well balanced and regulated sleep and circadian rhythms are recognized as principles that allow athletes to gain an advantage over opponents. Poor sleep puts athletes at risk of serious injury and slows the pace of recovery which in turn can negatively affect training and improvement.

Symptoms of sleep disorders can differ depending on type and severity of the specific disorder. Some of the general symptoms of sleep disorders include:

  • Difficulty falling asleep or staying asleep
  • Daytime fatigue and sleepiness
  • Strong urge to take naps during the day
  • Irritability or anxiety
  • Lack of concentration
  • Forgetfulness
  • Depression

To achieve optimal health and best performance a professional athlete must follow recommended training, nutritional, sleep and circadian rhythms guidelines. This may vary for individuals but there are many commonalities. Sleep is one of the most important circadian rhythms which is intertwined with the occurrence of many other circadian rhythms.  Sleep duration can be analyzed according to age and physical conditions of the individual. But its timing and quality have more to do with entrainment of the circadian rhythms as a system.

Sleep regulation and scheduling are supported by providing optimum conditions for sleep which rely on a balanced and entrained circadian rhythms. The timing of bright light exposure, eating and training time are as important as the timing of sleep itself. There are five known environmental cues that entrain the circadian rhythms. Regulation and scheduling of these cues allow for optimal conditions for well regulated circadian rhythms. These five cues in order of importance are:


  1. Bright light or morning sun which directly activates dedicated photoreceptors in the retina which in turn send a direct signal to Suprachiasmatic Nucleus (biological master clock) in the brain to start the day rhythms.
  2. The timing of the meals which triggers some of the peripheral circadian rhythms that have to be harmonized with the master clock timing.
  3. Physical activity or timing of exercise which helps to entrain certain daily rhythms which are crucial to our mental and physical health. Certain hours of the day are most suitable for training and physical work.
  4. Social interaction is another trigger for entrainment of the circadian rhythms.
  5. The ambient temperature of the sleeping environment. This is an important condition for timing and quality of sleep.

To entrain and maintain well-balanced circadian rhythms, which ensure optimum health and peak physical and mental performance, one can follow a daily schedule with minimal variations. Early hour’s exposure to bright light is crucial which can start the process and set the circadian rhythms for the day in response to the natural environment. As the sunlight is 10 to 50 times brighter than any usual artificial source, a bright sunny environment is recommended during the early hours of the day. Similarly as important is the darkness at night. Modern living causes a major problem here as we are all living with bright electric lighting and electronic screens at night, when our master clock needs to be set for the night mode. As a result we do not get sufficient darkness time. 

The timing of the breakfast and dinner, first and last meals of the day, are extremely important to appropriate entrainment. A restricted-feeding period of 6-8 hours per 24 hours is recommended for best result. If breakfast is consumed around 10:00 in the morning the dinner should be consumed by 6:00 pm max. After the last meal of the day only water is allowed. Most nutrition scientists still recommend the bigger meal of the day to be consumed in the morning and the day feeding should end with a small dinner. Water intake is extremely important throughout.

The timing of physical exertion or training can coincide with peak performance time according to individual’s circadian rhythms to maximize athletic gain while minimizing the risk of injury. If one wakes up and starts the day around 7:00 am then their greatest cardiovascular efficiency and muscle strength occurs around 5:00 pm. Therefore scheduling the training sessions around that time is most beneficial.

Social interaction has proven to have a positive effect on circadian rhythms entrainment and physical and mental health.

Finally, a dark bedroom at least couple degrees cooler than your normal daily environment is a must for better and timely sleep.   



Early exposure to bright light is one of the most important cues in entraining of the circadian rhythms for optimal health. The key, however, is in the oscillation between the bright light of the day and the total darkness of the night. While the bright light signals the daybreak, the lack of it at night signals arrival of night and beginning of the night rhythms. It is specifically the blue portion of light that signals the daybreak to our biological clock and resets it to day rhythms. Therefore, it is very important to realize that while the bright light is very important for the daytime setting, the total darkness is essential for the nighttime setting of the circadian rhythms.

The problem occurs at night when natural environment is polluted with artificial lights that are capable to signal the daybreak to our master clock even at late hours. Electronic screens, TV screens, and electric light bulbs have disturbing effects both on our sleep patterns and circadian rhythms.

Artificial lights emit enough blue light that can suppress production and secretion of melatonin. Melatonin is a hormone which promotes sleep, entrains circadian rhythms, boosts the immune system, and takes care of daily oxidative damage at a cellular level in our body. It is by far the most potent source of antioxidant known. Melatonin is a restorative agent which helps recovery at all levels.



Circadian Eyewear is a tested virtual darkness device blocking 99% of blue lights. Wearing the Circadian Eyewear 2 hours before regularly scheduled sleep promotes production and secretion of melatonin by blocking the blue portion of the light from reaching the retina.

Located in the brain, and in direct contact with dedicated photoreceptors which are capable of only reading the blue light, the master clock sees lack of blue light as total darkness. This condition is also called virtual darkness; meaning a total darkness to the master clock, but only a partial darkness to the eye.

While the production and secretion of melatonin starts after 30 minutes of wearing the glasses and secretion of cortisol subsides to its minimum the brain gets the body ready for the night rhythms and recovery.

Dubbed night hormone or sleep hormone, melatonin promotes rest and sleep. Meanwhile one can carry on with normal before bedtime activities such as reading, watching TV, or socializing.

Circadian Eyewear Collection
Circadian Eyewear



Research from PubMed

Sleep in Elite Athletes and Nutritional Interventions to Enhance Sleep

Relationships Between Training Load, Sleep Duration, and Daily Well-Being and Recovery Measures in Youth Athletes.

Sleep and Athletic Performance.

Sleep and athletic performance: the effects of sleep loss on exercise performance, and physiological and cognitive responses to exercise.

Sleep and Recovery in Team Sport: Current Sleep-Related Issues Facing Professional Team-Sport Athletes.

Research Sources