Can Exposure to Electric Light be Dimming Your Athletic Performance?
by Melinda Burris Willms
The invention of electric light was certainly a boon for technological progress, but researchers have noted that ready access to this artificial light source on a 24/7 basis has had deep repercussions not only for humankind but also for wildlife. Circadian disruption, or the confusion the mind and body can experience by being exposed to light around the clock, has been observed to have had numerous negative impacts across ecological systems. Wildlife with habitats in close proximity to urban areas that remain well-lit throughout the night have been observed to experience significant disruption in their natural migration patterns, methods of seeking food, and their normal immune and reproductive processes.1
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Researchers have gathered convincing evidence of numerous negative health impacts experienced by people who suffer from circadian disruption due to be being subjected to too much artificial light during the night hours when the sleep cycle naturally occurs. Causal links between environmental exposure to excessive amounts of artificial light during the night and increased propensity to develop a variety of physical maladies ranging from breast cancer to metabolic disorders have been established.1
The Internal Circadian Clock and Brain Function
A 24-hour day divided into portions of light and dark is engrained in the very essence of human psychology, as evidenced by the suprachiasmatic nucleus (SCN), which is found in the hypothalamus section of the brain. The hypothalamus is located in the forebrain and is responsible for regulating critical body processes including body temperature, appetite, thirst, the sleep cycle, and the autonomic nervous system which controls involuntary body functions such as breathing and heartbeat. That this central area of the brain responsible for so many essential processes to maintaining life is also responsible for regulating our natural circadian clock, highlights the essential role that 24-hour cycle plays in maintaining our good physical and mental health.2
Scientific studies underscore how much normal life function is centered around the circadian cycle. An investigative study conducted by MIT researchers in 2013 concluded: “Just about everything that takes place physiologically is really staged along the circadian cycle.”2 Given this fact, it is only natural that athletes should wonder how failing to maintain a normal circadian rhythm could affect their ability to perform.
Sleep Deprivation: How Athletes Could be Impacted Physically and Mentally
In 2014, Thuna et al., conducted an exhaustive comprehensive literature review of 113 scholarly journal articles examining the question of how circadian rhythm disruption and disfunction has been shown to effect athletic prowess. In designing this study, the researchers chose to exclude all studies that only dealt with forms of exercise that required short durations of sustained physical effort based on the concept that even those suffering from an abnormal circadian cycle could manage to perform those types of physical endeavor with minimal perceptible change in their overall performance. Therefore, the research selected for review focused on endurance sports where lack of sleep and alterations in mood and emotion caused by circadian cycle disruption could be clearly observed.3
The study results found a marked decline in the ability to sustain anerobic exercise when athletes were sleep deprived. One experiment with a focus on the effects of lack of sleep and the ability to maintain intense, prolonged physical exertion showed that participants required to perform repetitive deep squats over a 50-minute time span exhibited obvious signs of decline in performance after having been kept awake for only 30 hours. Subjects were also tested on their ability to maintain knee extensor strength following the 50-minute test time. Although participants covered approximately the same amount of distance over the full time allotted for the protocol testing, substantial decreases in participants’ starting times (the initial 10 minutes of the exertion test) and the strength of their finish were observed. A noticeable decline was observed in the amount of distance the study participants were able to cover in the final 10 minutes of the test.3
Numerous studies were cited in the literature review noting how even short times without sleep significantly impacted performance, particularly endurance. In one group, participants that were deprived of sleep for a single night demonstrated a discernable inability to match the distance they had covered walking on a treadmill before their sleep pattern was disrupted. Being kept from sleep for longer periods, 36 and 50 hours respectively, demonstrated that participants reached exhaustion times significantly faster than they had before being deprived of sleep.3
As circadian cycle disruption is known to affect the mental state as well as physical capabilities, a 2009 scientific study concentrated on how the moods and emotions of subjects asked to do physical activity while being deprived of sleep were impacted. Participants for this study included 11 males, all certified as healthy prior to the implementation of the experiment. The first night, the participants were allowed a normal night’s sleep before being required to complete a series of tests that researchers administered every four hours beginning at 6 a.m. on the first day and concluding twenty hours later at 2 a.m. on the second day. The subjects were then allowed a regular night’s sleep.. The test protocol resumed, with tests being administered for twelve straight hours. Participants were observed and monitored for a number of variables including “profile of mood states (POMS)” and the speed and energy of “self-chosen work rates.”4 In addition to physical observation, participants were required to fill out surveys and maintain a journal documenting what they did over the course of the experiment. Study results revealed a pronounced depression of mood on the first day.4
Strategies for Keeping Your Circadian Cycle on Track
Experts recommend that you avoid unnecessary stimuli at night, beginning with turning off artificial light sources and technological devices such as computers, smartphones, and televisions at least an hour before bedtime. Also, bear in mind that our bodies were designed with a need for natural light; be sure to get outside at least once a day and avoid overuse of artificial light sources by staying out of dark and windowless rooms.2
Conclusion
As noted by the 2013 MIT study, basically all of our functions, physical and mental, are informed and influenced by the circadian cycle. It is imperative that athletes seeking to function at their highest capacity allow their minds and bodies the stimulation and recovery phases the 24-hour circadian cycle provides.
References
- Bedrosian, T. A., and Nelson, R. J. (2017). Timing of Light Exposure Affects Mood and Brain Circuits.
- Bergland, C. (14 July 2016). Too Much Artificial Light Exposure Can Make You Sick.
- Thuna, E., et al. (20 November 2014). Sleep, Circadian Rhythms, and Athletic Performance.
- Meney, I. et al. (7 July 2009). The Effect of One Night’s Sleep Deprivation on Temperature, Mood, and Physical Performance in Subjects with Different Amounts of Habitual Physical Activity.
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