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

Abstract

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 (Δ SOL = 8 min). This effect was stronger (Δ 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.

A practical guide to improve sleep and performance in athletes

“…40 Similarly, a combination of blue light–blocking amber glasses in the evening and light-emitting goggles in the morning reduced self-reported sleep onset latency. 42 In a sample of teenagers, blue light–blocking amber glasses, even with exposure to devices, reduced the suppression of melatonin and made participants less alert before bed. 43 For people with insomnia, wearing blue light–blocking amber glasses for 2 hours before bedtime resulted in greater sleep duration and quality.…”

Troubleshooting a Nonresponder: Guidance for the Strength and Conditioning Coach

“…As a result, the use of amber lens glasses to block blue light in the evening has been investigated. Recreational athletes wearing amber glasses in the evening have shown improvements in sleep-by subjective ratings, but not actigraphy-when paired with morning light exposure protocols [123,124]. Due to the reality that many athletes are students, restricting screen time may be an impractical option-particularly due to the technological shift in education brought about by the COVID-19 pandemic.…”

Are there effects of light exposure on daytime sleep for rotating shift nurses after night shift?: an EEG power analysis

“…However, owing to circadian rhythm misalignment, night-shift workers may face difficulties in maintaining quality daytime sleep. In particular, exposure to strong lights during nighttime work has been associated with a disrupted circadian system ( Yoon et al, 2002 ; Knufinke et al, 2021 ), lowered sleep efficiency ( Martin et al, 2015 ), decreased time in bed ( Choi and Joo, 2016 ), and attenuated alertness (or wakefulness) after waking ( Yoon et al, 2002 ; Chang et al, 2015 ; Esaki et al, 2019 ). Furthermore, light exposure during sleep can impair glucose homeostasis, potentially via increased sympathetic nervous system activation ( Mason et al, 2022 ).…”