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. This is the biological foundation for both performance and recovery effects. 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 review raised the question of whether photobiomodulation should be assessed by international athletic regulatory bodies given the consistency and magnitude of its effects on performance.
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. Understanding which of these mechanisms is most relevant to a given training goal helps determine optimal timing.
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 conducted 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. The researchers suggested that pre-exercise treatment may also assist with post-injury strength-building and rehabilitation.
A separate 2018 study assigning 16 male athletes to four groups found that all three treatment groups receiving red light before exercise showed significantly reduced muscle fatigue compared with the control group that received no treatment. 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, demonstrating a carry-through effect that extends well beyond the session itself.
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. This is one of the more surprising findings in the research and one that most guides gloss over.
The reason for this window is biological. Photobiomodulation initiates a cellular signalling cascade through mitochondrial activation, nitric oxide release, and ATP upregulation. This cascade takes time to fully develop. When sessions are performed 3 to 6 hours before training, the mitochondrial priming effect peaks during the training window itself, 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. The performance priming effects are somewhat diminished but not absent. Immediate pre-workout use is the most common real-world protocol and is well supported.
- 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
- Focus area: the primary muscle groups to be trained in that session
Who benefits most from pre-workout use
Pre-workout sessions are most beneficial for people focused on performance output, 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 or high-frequency 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. Effects were greatest when treatment was applied within two hours of exercise completion.
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. The identical twin design eliminates genetic variability as a confound, making this a particularly clean piece of evidence for post-workout efficacy. A 2011 study involving 36 male participants also found that red light applied immediately after a leg press exercise increased subsequent muscle performance compared with strength training alone.
Optimal post-workout timing
Post-workout sessions should be performed as soon as possible after training for maximum effect. The acute inflammatory response that drives DOMS begins within minutes of exercise completion, and early photobiomodulation modulates this response before it fully establishes. Research protocols typically apply treatment within 30 minutes to two hours of exercise completion.
Sessions performed on the same day but several hours later still produce meaningful recovery benefits, but the window of greatest effect is the immediate post-workout period. For practical purposes, having your device accessible at home and using it within an hour of returning from training is the most effective approach for most people.
- 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
- Focus area: all major muscle groups trained in the session, including secondary movers
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, older athletes whose natural recovery rate has slowed, and anyone training multiple days in a row where recovery quality directly determines the next session's output.
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. These results were superior to pre-only or post-only protocols in separate studies, suggesting the two mechanisms compound rather than duplicate each other.
Pre-workout priming and post-workout recovery address different phases of the training cycle. Using both means muscles enter each session already primed and exit each session with recovery accelerated. Over a 12-week training block, the cumulative effect on training quality, volume, and adaptation is substantial.
For people using red light therapy at home with a panel, 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. This requires no additional time at the gym and integrates naturally into a home-based routine.
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 compared to post-workout. The mechanism is mitochondrial priming improving energy availability during resistance exercise, allowing higher training volume before fatigue limits performance.
Target the specific muscle groups to be trained. For a leg session, apply the device to the quadriceps, hamstrings, and glutes for 5 to 10 minutes before training. For an upper body session, cover the chest, shoulders, and back. Post-workout use for strength training is equally valid for recovery between sessions and for DOMS management when training frequency is high.
Endurance training
For endurance athletes including runners, cyclists, and swimmers, 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, as the mitochondrial priming effect on aerobic energy production is the primary mechanism for endurance benefit.
Post-workout use for endurance athletes is particularly valuable for managing cumulative training load across high-volume training weeks, as the anti-inflammatory and muscle repair effects help maintain tissue quality when sessions are daily or twice daily.
Team sports and court sports
For team sport athletes including football, basketball, and tennis players, where explosive output, agility, and repeated sprint capacity are the 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, particularly in heavy training blocks or around competition.
CrossFit and HIIT
High-intensity training modalities produce significant metabolic and mechanical stress in short timeframes. Both pre and post-workout use are well justified. Pre-workout priming supports the explosive output and high repetition demands of CrossFit and HIIT. Post-workout use is essential for managing the significant DOMS that high-intensity training reliably produces, particularly when sessions are daily.
What to Do When Training Twice a Day
Twice-a-day training places significant recovery demands on the body and is where red light therapy provides some of its most meaningful practical benefit. The key question is where to place sessions relative to the two training windows.
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. If time allows a third session at the end of the day, a short post-evening-session treatment closes out the day with recovery support.
- 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
For people using a portable wearable device, the between-session window is also practical for passive treatment during rest, travel, or work.
StreamShop Devices for Training and Recovery
Different training goals and session formats suit different devices. The following StreamShop options cover the range from targeted localised treatment to full-body performance protocols.
SR72 Panel
StreamShop's SR72 red light therapy panel delivers 660nm and 850nm wavelengths at 139 mW/cm² at 15cm across 72 dual-chip LEDs. For pre-workout sessions targeting specific muscle groups before training, and post-workout sessions covering the primary trained muscles, the SR72 is a practical and well-priced starting point. Its desktop stand allows hands-free positioning over the target area during a pre or post-workout session.
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, particularly for localised areas like the quadriceps, hamstrings, lower back, or shoulders. 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 where session time between workouts is limited.
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. For athletes prioritising maximum performance output and recovery, the higher irradiance and deeper-penetrating wavelengths deliver more dose per unit time and better penetration to deep muscle tissue, which is particularly relevant for larger muscle groups like the quadriceps, hamstrings, and back where adequate depth of penetration matters most.
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 rather than requiring sequential positioning. The 1064nm wavelength provides the deepest tissue penetration of any StreamShop device, 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 and are training at high intensity or high frequency. 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 for muscle damage prevention and fatigue reduction. 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.
Red light therapy before workout: does it 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 indicating less muscle damage, and improve time-to-exhaustion in aerobic protocols. The evidence is consistent across multiple research groups and exercise modalities.
Red light therapy after workout: how much does it speed up recovery?
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. This translates directly to higher training frequency and quality as sessions can be performed at greater intensity sooner after previous training.
Can I use red light therapy every day for training?
Yes. Unlike physical training itself, which requires rest days for adaptation, 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. Consistency of use is one of the strongest predictors of cumulative benefit.
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. For post-workout use after a full-body session, prioritise the muscle groups that received the highest load. The portable pad is most practical for targeted localised treatment, while a larger panel covers multiple groups simultaneously.