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Published on: 4/24/2026

Beating the Burn: RLT for Delayed Onset Muscle Soreness

Red light therapy (RLT) uses specific 600-900 nm red and near-infrared light to stimulate cellular energy production, reduce inflammation and improve blood flow, helping to ease delayed-onset muscle soreness and speed recovery after high-intensity workouts.

There are several factors to consider including device choice, treatment timing, safety precautions and how RLT fits into a holistic recovery plan, so see below for all the important details to guide your next steps in optimizing performance and knowing when to seek medical advice.

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Explanation

Beating the Burn: Red Light Therapy for Delayed Onset Muscle Soreness

Delayed onset muscle soreness (DOMS) is a familiar foe for anyone pushing their limits—especially CrossFit athletes who thrive on high‐intensity, varied workouts. Stiffness, aching muscles and decreased performance can linger for days, slowing your progress. Red light therapy (RLT) is emerging as a promising, noninvasive tool to ease DOMS and help you get back in the box stronger, faster.

What Is Red Light Therapy?

Red light therapy (sometimes called low‐level laser therapy or photobiomodulation) uses specific wavelengths of red and near-infrared light (600–900 nm) to penetrate skin and muscle tissue. Unlike ultraviolet rays, these wavelengths do not damage DNA. Instead, they:

  • Stimulate cellular energy production (ATP)
  • Improve blood flow and oxygen delivery
  • Reduce inflammation and oxidative stress

This cellular boost supports faster recovery, less pain and better range of motion—key for CrossFit athletes tackling Olympic lifts, WODs and gymnastic elements.

How RLT Works for Muscle Recovery

At a basic level, RLT helps cells function more efficiently. Here's how:

  1. Photoreceptors in mitochondria absorb red/near-infrared light.
  2. Mitochondrial activity ramps up, producing more ATP (cellular "fuel").
  3. Increased ATP accelerates repair of microtears and supports muscle protein synthesis.
  4. Anti-inflammatory pathways are activated, reducing swelling and pain.
  5. Enhanced circulation clears metabolic waste (like lactic acid) faster.

The result: less soreness, faster return to peak performance and reduced risk of overtraining.

Evidence Behind Red Light Therapy for DOMS

Several studies support RLT's benefits in easing DOMS and improving functional recovery:

  • A 2016 randomized trial in the Journal of Strength and Conditioning Research found athletes who received near-infrared therapy before eccentric exercise reported significantly less soreness up to 72 hours post-workout.
  • Research published in Lasers in Medical Science (2017) demonstrated that red light therapy applied immediately after intense exercise reduced biomarkers of muscle damage (creatine kinase) and inflammation.
  • A 2020 meta-analysis in Photomedicine and Laser Surgery concluded that RLT "substantially reduces pain and accelerates recovery" in individuals experiencing DOMS.

These peer-reviewed studies underline how RLT can be a valuable addition to your recovery toolbox.

Benefits of Red Light Therapy for CrossFit Athletes

CrossFit workouts stress multiple muscle groups with explosive movements, making DOMS a frequent challenge. RLT offers:

  • Rapid relief: Many users report reduced stiffness and pain within hours of a session.
  • Improved performance: By shortening recovery time, you can maintain training intensity and consistency.
  • Non-invasiveness: No needles, no drugs, no side-effects typical of oral analgesics.
  • Versatility: Can be applied at home, at the gym or at a training facility.
  • Cumulative effects: Regular use enhances mitochondrial health, supporting long-term resilience.

Incorporating Red Light Therapy into Your Routine

Getting started with RLT is straightforward. Here's a sample protocol:

  1. Choose your device

    • Handheld panels or full-body beds
    • Look for 600–900 nm wavelength LEDs, power output ≥ 20 mW/cm²
  2. When to use it

    • Pre-workout: 5–10 minutes to prime muscles and improve circulation
    • Post-workout: 10–15 minutes to kickstart recovery processes
  3. How to position

    • Keep the light source 6–12 inches from skin
    • Target major groups: quads, hamstrings, glutes, shoulders, back
  4. Treatment frequency

    • 3–5 times per week for chronic issues
    • Daily sessions during high-volume cycles
  5. Duration

    • 5–15 minutes per area, depending on device intensity

Safety and Considerations

Red light therapy is generally safe, but keep these tips in mind:

  • Never stare directly into high-intensity LEDs—wear protective goggles if provided.
  • Avoid using RLT over active infections, open wounds or areas with suspected malignancy.
  • If you have photosensitive conditions or take photosensitizing medications, speak to your doctor before starting RLT.
  • Results may vary; not everyone experiences dramatic relief on day one. Give your body time to adapt.

Monitoring Symptoms and Knowing When to Seek Help

While RLT can ease common workout soreness, severe or unusual pain may signal a more serious issue—such as muscle tears, rhabdomyolysis or joint damage. If you experience:

  • Intense, sharp pain that worsens over time
  • Swelling, redness or warmth beyond normal muscle fatigue
  • Dark or tea-colored urine (possible rhabdomyolysis)
  • Numbness, tingling or loss of function

…get personalized guidance instantly with Ubie's free Medically Approved LLM Symptom Checker Chat Bot. It can help you determine the severity of your symptoms and whether you need immediate medical attention.

Always "speak to a doctor" about anything that could be life-threatening or serious.

Maximizing Recovery Beyond Red Light Therapy

RLT works best as part of a holistic approach. Don't neglect:

  • Proper Nutrition
    • Adequate protein (1.6–2.2 g/kg body weight) to support muscle repair
    • Carbohydrates to refill glycogen stores
    • Antioxidants (vitamins C, E) to neutralize free radicals

  • Quality Sleep
    • Aim for 7–9 hours per night
    • Practice good sleep hygiene: consistent schedule, dark room

  • Active Recovery
    • Light cardio, mobility drills or yoga on rest days
    • Foam rolling and targeted stretching

  • Hydration & Electrolytes
    • Replace fluids lost during WODs
    • Incorporate sodium, potassium and magnesium

Final Thoughts

Red light therapy is a scientifically backed, user-friendly strategy to reduce DOMS and support CrossFit performance. By stimulating cellular repair, improving blood flow and taming inflammation, RLT helps you bounce back quicker and stay consistent in your training.

Remember: RLT is not a magic bullet. Combine it with sound nutrition, sleep, hydration and active recovery for the best results. And when in doubt—especially if you suspect a serious injury—use a Medically Approved LLM Symptom Checker Chat Bot and "speak to a doctor" to ensure you stay safe and healthy on your fitness journey.

(References)

  • * Corazza, T. M., et al. (2023). Effect of photobiomodulation therapy on exercise-induced muscle damage and delayed onset muscle soreness in healthy individuals: a systematic review and meta-analysis of randomized controlled trials. *Lasers Med Sci*, 38(1), 226. [PMID: 37728472]

  • * Yang, R., et al. (2022). Effect of Photobiomodulation Therapy on Delayed Onset Muscle Soreness: A Systematic Review and Meta-Analysis. *J Clin Med*, 11(23), 7083. [PMID: 36555981]

  • * de Vasconcelos, I. A. L., et al. (2020). Effect of red light therapy on delayed onset muscle soreness (DOMS) in physically active individuals: A systematic review and meta-analysis. *J Photochem Photobiol B*, 208, 111902. [PMID: 32679549]

  • * Vanin, A. A., et al. (2018). The effect of photobiomodulation therapy on performance and recovery in resistance training: a systematic review and meta-analysis. *Lasers Med Sci*, 33(9), 1877-1887. [PMID: 28940026]

  • * Leal-Junior, E. C. P., et al. (2015). Photobiomodulation for Exercise-Induced Muscle Damage and Delayed-Onset Muscle Soreness: A Systematic Review and Meta-analysis of Randomized Controlled Trials. *Lasers Med Sci*, 30(5), 1827-1837. [PMID: 25772390]

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