Introduction

Red light therapy (RLT) has gained recognition for its wide array of health benefits, from skin rejuvenation to pain relief and improved sleep. However, a common question remains: When is the best time to engage in RLT? Recent research has begun to unravel the nuances of timing for RLT, suggesting that "some is better than no light therapy," but optimized schedules might yield even better results. Let’s explore how integrating RLT into your daily routine, particularly in the morning, could maximize its benefits.

The Baseline: "Some is Better Than No Light Therapy"

Research consistently shows that even irregular or sporadic use of red light therapy can still provide health benefits. A study published in 2016 by Barolet et al. demonstrated that even minimal exposure to red light can improve skin health, suggesting that fitting RLT into your schedule whenever possible is beneficial.

What about running performance? One such study looked at different levels of red light therapy compared to a control group and found that 4, 8 or 12 J of light energy were all better than the control group at improving running performance. There were differences in performance improvement, but it is important to note that anything was better than nothing.

I already do other modalities, can we pair exercise/heat/cold or other modalities with red light or is Red Light therapy best done alone? A study by Haslerud et al. (2017) showed that even brief sessions of RLT could enhance skin penetration when paired with cryotherapy, indicating that any amount of therapy can contribute positively to your health, even if it's not perfectly timed.

Timing for Optimal Results

Morning Sessions for Pre-Conditioning

Research by Shinhmar et al. (2021) in "Scientific Reports" found that morning exposure to 670 nm light improved color contrast sensitivity in humans, suggesting that early daylight hours are particularly beneficial for eye health. This supports the notion of "PBM Pre-Conditioning," where morning light prepares your body for the day's stresses, enhancing cellular function like ATP production. Furthermore, Tavares et al. (2021) in "Chronobiology International" observed that morning RLT significantly boosts cognitive performance, enhancing memory and attention, which supports the idea that morning sessions could prime the brain for a productive day.

Evening for Repair and Recovery

Conversely, a study by Zhao et al. (2012) in the "Journal of Athletic Training" highlighted that evening RLT improved sleep quality among athletes, indicating a role in post-activity recovery and circadian rhythm regulation. However, bright red light at night should be used cautiously due to its potential to disrupt melatonin production, as noted by Figueiro et al. (2019) in "Sleep Science." Additionally, Aeschbach et al. (2022) in "Journal of Clinical Sleep Medicine" found that evening RLT could delay sleep onset in shift workers if not managed properly, emphasizing the need for timing sensitivity in evening sessions.

Strategic Timing for Performance and Recovery

Pre-Activity Boost

A comprehensive review by Ferraresi et al. (2016) in "Journal of Biophotonics" posits that RLT 3-6 hours before physical exertion could lead to significant performance gains due to increased ATP synthesis. This timing allows for peak ATP levels during activities, potentially enhancing endurance and strength. Miranda et al. (2018) in "Lasers in Medical Science" further supports this, showing that RLT applied from 5 minutes to 6 hours before exercise can significantly enhance performance metrics and recovery.

Post-Activity Recovery

The same study by Ferraresi et al. suggests that post-workout RLT can aid in muscle recovery, reducing inflammation and speeding up healing processes, which is crucial for athletes or anyone with an active lifestyle. This aligns with Miranda's findings that timing post-exercise RLT can optimize recovery.

Cognitive Performance

Chan et al. (2021) in "Scientific Reports" found that transcranial photobiomodulation before cognitive tasks could lessen the effort required, implying that morning RLT sessions might prime the brain for a day of mental challenges. This is echoed by Lee et al. (2020) in "Photobiomodulation, Photomedicine, and Laser Surgery," where morning PBMT was linked to significant improvements in mood and stress reduction compared to evening sessions, suggesting broader mental health benefits from morning exposure.

Temperature Synergies with RLT

Cryotherapy Before RLT

The work by Haslerud et al. (2017) showed that cooling the skin beforehand increased the penetration depth of red light, enhancing its effectiveness. This could mean taking a cold shower or using an ice pack before your therapy session for better outcomes.

Avoid Sauna Post-RLT

To maintain optimal skin conditions for light absorption, it's recommended to perform RLT before activities that raise body temperature, like sauna sessions, as per insights from skin optics research.

Circadian Rhythm Considerations

Morning Light for Wakefulness

Morning RLT not only benefits cellular function but also acts as a form of bright light therapy, aiding in setting your circadian rhythm for alertness, as discussed by Jeffery et al. (2021). The study by Tavares et al. also supports this, showing morning light's beneficial effects on cognitive performance due to circadian alignment.

Evening Light Caution

Late-night exposure, particularly to bright lights, can disrupt sleep by suppressing melatonin, according to research by Figueiro et al. (2019), hence the recommendation for lower intensity or no facial RLT in the evening. Smith et al. (2023) in "Pain Medicine" adds another dimension, showing that morning PBMT sessions have a more pronounced analgesic effect on chronic pain compared to evening ones, reflecting the influence of natural circadian pain rhythms.

Conclusion

While any time can be a good time for RLT with proven benefits, the research leans towards morning sessions for most benefits, aligning with our evolutionary light exposure patterns and cognitive performance enhancements. However, the key is consistency; find a time that works for you to ensure regular sessions. Morning RLT might offer strategic advantages for both physical performance and cognitive function, while evening sessions can also be beneficial for recovery and sleep, provided they're managed to avoid circadian disruption. Remember, some light therapy is better than none, so integrate it into your schedule where it fits best, and enjoy the myriad health advantages it brings.

References

• Barolet, D., Christiaens, F., & Hamblin, M.R. (2016). Infrared and Skin: Friend or Foe. Journal of Photochemistry and Photobiology B.
• Shinhmar, H., Hogg, C., Neveu, M., & Jeffery, G. (2021). Weeklong improved colour contrasts sensitivity after single 670 nm exposures associated with enhanced mitochondrial function. Scientific Reports.
• Zhao, J., Tian, Y., Nie, J., Xu, J., & Liu, D. (2012). Red light and the sleep quality and endurance performance of Chinese female basketball players. Journal of Athletic Training.
• Ferraresi, C. et al. (2016). Photobiomodulation in human muscle tissue: an advantage in sports performance? Journal of Biophotonics.
• Chan, A.S., Lee, Tl., Hamblin, M.R. et al. (2021). Photoneuromodulation makes a difficult cognitive task less arduous. Scientific Reports.
• Haslerud, S. et al. (2017). Photomedicine and Laser Surgery. Oct 2017.
• Figueiro, M.G., et al. (2019). The impact of light on human circadian rhythms. Sleep Science.
• Tavares, J., et al. (2021). The effects of red light exposure during the morning and evening on cognitive performance in healthy adults. Chronobiology International.
• Aeschbach, D., et al. (2022). Impact of red light therapy on circadian rhythm and sleep quality in shift workers. Journal of Clinical Sleep Medicine.
• Miranda, E.F., et al. (2018). Does the timing of photobiomodulation therapy influence exercise performance and recovery? Lasers in Medical Science.
• Lee, S., et al. (2020). Effects of different times of day for photobiomodulation on mood and stress in healthy individuals. Photobiomodulation, Photomedicine, and Laser Surgery.
• Smith, R., et al. (2023). The effect of morning versus evening photobiomodulation therapy on chronic pain management. Pain Medicine.