Dim light, sleep tight, and wake up bright - Sleep optimization in athletes by means of light regulation

Melanie Knufinke*, Arne Nieuwenhuys, Sabine A. E. Geurts, Els I. S. Most, Maarten H. Moen, Kamiel Maase, Anton M. L. Coenen, Marijke C. M. Gordijn, Michiel A. J. Kompier

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Despite an elevated recovery need, research indicates that athletes often exhibit relatively poor sleep. Timing and consolidation of sleep is driven by the circadian system, which requires periodic light-dark exposure for stable entrainment to the 24-hour day, but is often disturbed due to underexposure to light in the morning (e.g. low-level indoor lighting) and overexposure to light in the evening (e.g. environmental and screen-light). This study examined whether combining fixed sleep schedules with light regulation leads to more consolidated sleep. Morning light exposure was increased using light-emitting goggles, whereas evening light exposure was reduced using amber-lens glasses. Using a within-subject crossover design, twenty-six athletes (14 female, 12 male) were randomly assigned to start the intervention with the light-regulation-week or the no light-regulation-week. Sleep was monitored by means of sleep diaries and actigraphy. Due to low protocol adherence regarding the fixed sleep-wake schedules, two datasets were constructed; one including athletes who kept a strict sleep-wake schedule (N = 8), and one that also included athletes with a more lenient sleep-wake schedule (N = 25). In case of a lenient sleep-wake schedule, light regulation improved self-reported sleep onset latency (Delta SOL = 8 min). This effect was stronger (Delta SOL = 17 min) and complemented by enhanced subjective sleep quality in case of a strict sleep-wake schedule. None of the actigraphy-based estimates differed significantly between conditions. To conclude, light regulation may be considered a potentially effective strategy to improve subjective sleep, but less obtrusive methods should be explored to increase protocol compliance.

Original languageEnglish
Pages (from-to)7-15
Number of pages9
JournalEuropean Journal of Sport Science
Issue number1
Publication statusE-pub ahead of print - 20-Feb-2020
Externally publishedYes


  • Light regulation
  • sleep
  • athletes
  • blue-blocker glasses
  • light exposure

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