Red Light Therapy Before or After Workout: The Complete Guide

TL;DR

• Both pre-workout and post-workout red light therapy are supported by research, but they work through different mechanisms and produce different primary outcomes. Pre-workout primes muscles for performance. Post-workout accelerates recovery.
• For performance, strength, and endurance goals, pre-workout timing has the edge, with multiple studies showing reduced fatigue, higher repetitions to failure, and lower markers of muscle damage when red light is applied before training.
• For recovery, DOMS reduction, and injury management, post-workout timing is most effective, with documented reductions in soreness, inflammation, and recovery time that allow higher training frequency.
• Using red light therapy both before and after training produces the best overall results according to a 12-week randomised controlled trial, with significantly greater gains in time-to-exhaustion, oxygen uptake, and body fat reduction compared to placebo.
• If you can only choose one, post-workout is the more versatile option for most people. Managing recovery directly determines the quality of every subsequent session, making it the higher-leverage choice for consistent training.

Red light therapy has moved from fringe biohacking into mainstream sports science, with a substantial and growing evidence base documenting its effects on muscle performance, recovery, and injury prevention. For athletes and active people, the practical question is not whether it works but when to use it to get the most out of it.

This guide works through the science behind both pre and post-workout use, explains the optimal timing windows and why they exist, covers sport-specific protocols, addresses twice-a-day training scenarios, and matches StreamShop devices to different training goals.

How Red Light Therapy Affects Muscle and Exercise Performance

Red and near-infrared light is absorbed by mitochondria in muscle cells, increasing ATP production and reducing oxidative stress. A 2016 systematic review published in Lasers in Medical Science analysed 46 randomised controlled trials involving 1,045 participants and found that photobiomodulation applied before or after exercise increased muscle mass gained after training, decreased inflammation, and reduced oxidative stress in muscle biopsies.

The four key mechanisms relevant to exercise are: increased ATP production giving muscle cells more energy for contraction and repair; reduced reactive oxygen species that cause oxidative damage during intense effort; increased nitric oxide production improving blood flow and oxygen delivery to working muscles; and reduced pro-inflammatory cytokines that drive delayed onset muscle soreness.

Red Light Therapy Before a Workout

What the Research Shows

Pre-workout photobiomodulation acts as muscle preconditioning, priming the mitochondrial energy system before the metabolic demands of training begin. A 2018 study involving 48 male volunteers over 12 weeks found that pre-workout red light therapy led to significant improvements in muscle strength and mass compared with both post-workout and placebo groups. An earlier study on professional volleyball players found that pre-exercise red light applied 40 to 60 minutes before activity helped avoid muscle damage, with decreased creatine kinase markers maintained for 72 to 96 hours after treatment.

The 3 to 6 Hour Timing Window

The optimal window for pre-workout red light therapy is 3 to 6 hours before training for maximum performance effects. Photobiomodulation initiates a cellular signalling cascade through mitochondrial activation, nitric oxide release, and ATP upregulation. This cascade takes time to fully develop, meaning muscle cells are operating at maximum energy efficiency precisely when they are under load.

Practically, most people cannot structure their day around a 3 to 6 hour gap. Sessions performed immediately before training still produce meaningful benefits, particularly for muscle damage prevention and acute fatigue reduction.

• Ideal: 3 to 6 hours before training for maximum mitochondrial priming effect
• Practical: immediately before training for muscle damage prevention and fatigue reduction
• Session length: 5 to 15 minutes over the target muscle groups

Who Benefits Most From Pre-Workout Use

Pre-workout sessions are most beneficial for strength athletes wanting higher training volume, endurance athletes wanting to delay fatigue onset, people managing chronic joint or muscle pain who need muscles primed before loading, and anyone doing high-intensity training who wants to reduce acute muscle damage during sessions.

Red Light Therapy After a Workout

What the Research Shows

Post-workout photobiomodulation is the most extensively studied application in the exercise context. A 2012 systematic review in the European Journal of Sport Science found that post-exercise photobiomodulation significantly reduced delayed onset muscle soreness and accelerated recovery of muscle strength and function. A 2016 study on identical twins found that red light applied to the quadriceps immediately after a workout reduced muscle damage and pain and increased muscle mass, recovery, and athletic performance compared to the untreated twin.

Optimal Post-Workout Timing

Post-workout sessions should be performed as soon as possible after training for maximum effect. Research protocols typically apply treatment within 30 minutes to two hours of exercise completion.

• Ideal: within 30 minutes of completing training
• Still effective: up to 2 hours post-workout
• Session length: 10 to 20 minutes over the trained muscle groups

Who Benefits Most From Post-Workout Use

Post-workout sessions are most beneficial for people focused on recovery and training frequency, anyone experiencing significant DOMS that limits back-to-back sessions, people returning from injury who need to manage inflammation carefully, and older athletes whose natural recovery rate has slowed.

Using Red Light Therapy Both Before and After a Workout

The most comprehensive approach in the research is pre and post-workout treatment in the same training day. A 12-week randomised controlled trial involving 77 volunteers undergoing treadmill training found that participants who received red light both before and after sessions showed a significant increase in time-to-exhaustion and oxygen uptake, and a reduction in body fat, compared to placebo. Pre-workout priming and post-workout recovery address different phases of the training cycle, meaning the two mechanisms compound rather than duplicate each other.

The practical approach is a short pre-workout session of 5 to 10 minutes over the target muscles before leaving for training, then a longer post-workout session of 10 to 20 minutes on returning home.

Sport-Specific Protocols

Strength Training and Bodybuilding

For strength and hypertrophy goals, pre-workout timing has the strongest evidence, with the 2018 Brazilian trial showing greater muscle mass and strength gains with pre-workout treatment. Target the specific muscle groups to be trained for 5 to 10 minutes before training. Post-workout use is equally valid for recovery between sessions and DOMS management when training frequency is high.

Endurance Training

For endurance athletes, pre-workout use is most relevant for delaying lactate accumulation and improving time-to-exhaustion. The 3 to 6 hour pre-training window is worth implementing where scheduling allows. Post-workout use is particularly valuable for managing cumulative training load across high-volume training weeks.

Team Sports and Court Sports

For team sport athletes where explosive output and repeated sprint capacity are key performance demands, pre-workout use supports neuromuscular readiness and fatigue resistance. Post-workout use is critical for managing the high mechanical load that team sport training places on muscles and connective tissue.

CrossFit and HIIT

High-intensity training produces significant metabolic and mechanical stress in short timeframes. Both pre and post-workout use are well justified. Pre-workout priming supports explosive output demands. Post-workout use is essential for managing the significant DOMS that high-intensity training reliably produces.

What to Do When Training Twice a Day

The most effective approach for twice-a-day training is to use red light therapy after the first session and before the second. This prioritises recovery from the morning session while also priming muscles for the afternoon or evening session.

• After morning session: 10 to 20 minutes for recovery and inflammation reduction
• Before afternoon or evening session: 5 to 10 minutes for mitochondrial priming
• After evening session if possible: 10 minutes for overnight recovery support

StreamShop Devices for Training and Recovery

SR72 Panel

StreamShop's SR72 red light therapy panel delivers 660nm and 850nm wavelengths at 139 mW/cm² at 15cm. For pre-workout sessions targeting specific muscle groups and post-workout sessions covering the primary trained muscles, the SR72 is a practical and well-priced starting point.

Portable Red Light Therapy Pad

StreamShop's portable red light therapy pad with near-infrared is the most practical option for targeted muscle group treatment. Its wearable design allows passive treatment during rest between sessions, during commuting, or at the workplace, making it particularly valuable for twice-a-day training scenarios.

SS300 Pro Medical Grade Panel

StreamShop's SS300 Pro medical grade panel delivers 175.1 mW/cm² at 15cm across nine wavelengths including 1060nm near-infrared through a 30-degree focusing lens. The higher irradiance and deeper-penetrating wavelengths deliver more dose per unit time and better penetration to deep muscle tissue, particularly relevant for larger muscle groups like the quadriceps, hamstrings, and back.

Red Light Therapy Laser Bed

StreamShop's red light therapy laser bed uses 1064nm VCSEL laser technology for full-body treatment. For athletes doing full-body training sessions or high-volume sport involving systemic muscle load, full-body treatment covers all trained muscles simultaneously. The 1064nm wavelength provides the deepest tissue penetration, making it the most relevant option for post-workout recovery from high-load full-body training.

Frequently Asked Questions

Should I Use Red Light Therapy Before or After a Workout?

Both are supported by research. Use it before training if your primary goal is performance and strength output. Use it after training if your primary goal is recovery and managing DOMS. Use it both before and after if you want to maximise the benefits of both. If you can only choose one, post-workout is the more versatile choice for most people.

How Long Before a Workout Should I Use Red Light Therapy?

Research suggests 3 to 6 hours before training produces the maximum performance priming effect. In practice, immediately before training is the most common protocol and still produces meaningful benefits. Even a short 5 minute session immediately pre-training is better than no session.

How Long After a Workout Should I Use Red Light Therapy?

Within 30 minutes of finishing training is optimal. Up to two hours post-workout still produces meaningful recovery benefits. Sessions performed several hours after training are less effective for managing the acute inflammatory response but still support overnight recovery and tissue repair.

Does Red Light Therapy Before a Workout Actually Improve Performance?

Yes, according to multiple controlled studies. Pre-workout photobiomodulation has been shown to increase the number of repetitions performed before fatigue, reduce blood lactate accumulation during endurance exercise, decrease creatine kinase levels post-exercise, and improve time-to-exhaustion in aerobic protocols.

How Much Does Red Light Therapy Speed Up Recovery After a Workout?

Research documents significant reductions in DOMS at 24, 48, 72, and 96 hours after exercise in treated groups compared to placebo. Muscle strength recovery is also faster, with treated athletes returning to peak force output sooner than controls, allowing higher training frequency and quality.

Can I Use Red Light Therapy Every Day for Training?

Yes. Unlike physical training itself, red light therapy does not cause the micro-damage that necessitates recovery time. Daily use is safe and appropriate, and for people training daily it can be used every training day.

What Muscles Should I Target With Red Light Therapy for Workouts?

Target the primary muscle groups being trained in that session. For a leg session, cover the quadriceps, hamstrings, and glutes. For an upper body session, cover the chest, shoulders, and back. The portable pad is most practical for targeted localised treatment, while a larger panel covers multiple groups simultaneously.