Full-Body Photobiomodulation Therapy Is Associated with Reduced Sleep Durations and Augmented Cardiorespiratory Indicators of Recovery

Abstract

Research is emerging on the use of Photobiomodulation therapy (PBMT) and its potential for augmenting human performance, however, relatively little research exists utilizing full-body administration methods. As such, further research supporting the efficacy of whole-body applications of PBMT for behavioral and physiological modifications in applicable, real-world settings are warranted. The purpose of this analysis was to observe cardiorespiratory and sleep patterns surrounding the use of full-body PBMT in an elite cohort of female soccer players. Members of a women's soccer team in a "Power 5 conference" of the National Collegiate Athletic Association (NCAA) were observed across one competitive season while wearing an OURA Ring nightly and a global positioning system (GPS) sensor during training. Within-subject comparisons of cardiorespiratory physiology, sleep duration, and sleep composition were evaluated the night before and after PBMT sessions completed as a standard of care for team recovery. Compared to pre-intervention, mean heart rate (HR) was significantly lower the night after a PBMT session (p = 0.0055). Sleep durations were also reduced following PBMT, with total sleep time (TST) averaging 40 min less the night after a session (p = 0.0006), as well as significant reductions in light sleep (p = 0.0307) and rapid eye movement (REM) sleep durations (p = 0.0019). Sleep durations were still lower following PBMT, even when controlling for daily and accumulated training loads. Enhanced cardiorespiratory indicators of recovery following PBMT, despite significant reductions in sleep duration, suggest that it may be an effective modality for maintaining adequate recovery from the high stress loads experienced by elite athletes.

Keywords: athlete monitoring; exercise training; red light therapy; soccer; wearable device.

Figure 1

(A–C) Relationships between Total Sleep Durations and Nocturnal Physiology. The relationship between total sleep duration and nocturnal physiological parameters are demonstrated for both the night before and the night after a PBMT session, including (A) average HR, (B) average HRV, and (C) average RR. (HR, heart rate; hrs, hours; HRV, heart rate variability; ME, main effect; RR, respiration rate).

Figure 2

(A–D) Heart Rate Trends by Half of Night. Least squares means interaction plots demonstrating the effects of night half (first and second halves of each sleep period) and night (before or after PBMT intervention) on (A) Minimum HR (bpm). (B) Maximum HR (bpm). (C) Average HR (bpm). (D) Average rate of change in HR per hour (bpm/hour). (*) denotes significant pairwise differences between the first and second halves of the night before PBMT intervention, (§) denotes significant pairwise differences between first and second halves of the night after PBMT intervention, (‡) denotes significant pairwise differences between the night before and night after PBMT intervention during the first half of the night only, and (¥) denotes significant pairwise differences between the night before and night after PBMT during the second half of the night only. (bpm, beats per minute; half*night, interaction between half of night and night; HR, heart rate; ME, main effect).

Figure 3

(A–C) Heart Rate Variability Trends by Half of Night. Least squares means interaction plots demonstrating the effects of night half (first and second halves of each sleep period) and night (before or after PBMT intervention) on (A) Maximum HRV (ms). (B) Average HRV (ms). (C) Average rate of change in HRV per hour (ms/hour). (*) denotes significant pairwise differences between the first and second halves of the night before the PBMT intervention, (§) denotes significant pairwise differences between first and second halves of the night after the PBMT intervention, and (‡) denotes significant pairwise differences between the night before and night after PBMT intervention during the first half of the night only. (HRV, heart rate variability; ME, main effect; ms, milliseconds).

Figure 4

Relationship between Total Sleep Time and Daily Training Load. Single-day player loads (au) measured via GPS during training sessions are plotted against subsequent night sleep durations, occurring both the night before and night after a PBMT session. (hrs, hours; ME, main effect; night*PL, interaction between night and player load).