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Red Light Therapy Before Or After Workout: The Ultimate Guide

In this blog post, I explore whether red light therapy before or after workout is the best, and why, and break down all the science on this topic in great detail.

Red Light Therapy Before Or After Workout: The Ultimate Guide
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Red light therapy before or after workout sessions has become extremely popular. And, for good reason: many people experience huge benefits using this approach for their workout performance. Nevertheless, we frequently get the question of what red light therapy panel should be used to maximize workout performance. Also, people aren't sure whether they should use a red light therapy panel before or after workout sessions, or both.

So, I decided to dig deep into the science of red light therapy for workout performance. I've analyzed all the currently available science on this topic. During that process, I was amazed at how promising the current research on this topic already is. 

My recommendation?

Fasten your seatbelt and get ready for a tour de force through all of the red light therapy for workout performance science. First, I'll start with an introduction. If you're interested in just learning the outcome, then read the summary section below. At the end, I'll supply you with the best panels that I think will most increase your red light therapy before or after workout performance.

Here we go:

Red Light Therapy Before Or After Workout Performance Summary:

So here's the final outcome of my blog post on red light therapy before or after workout performance:

  • Generally, the outcomes of red light therapy are 100% supportive so far. No side effects have been found and all studies show a positive benefit, either for recovery, or maximum performance, or lactate levels, or pain.
  • Most studies have been carried out with the 808 or 810nm wavelength, not the 850nm wavelength. Any company telling you you only need 850nm is deceptive at the very least, if you consider red light therapy for workout performance. Some studies show good results with the high 800s and low 900s wavelengths.
  • Systematic reviews (summaries and integrations of existing research) confirm that picture: near-infrared light wavelengths are studied better and may be superior because they penetrate deeper, for muscle recovery. 
  • But you don't have to choose, however, then a combination of red and near-infrared light is best as red has independent benefits for mitochondria and more. Red light  arguably has independent benefits too, just fewer for the goal I'm considering here.
  • A large number of different benefits are found, such as less muscle soreness, better mitochondrial efficiency, greater muscle mass, strength and endurance gains in many studies, faster recovery, less pain, and more.
  • Systematic reviews also state the best time to use red light therapy is 3-6 hours before a workout, not just before a workout. Using red light therapy before a workout as opposed to after a workout also has a slight edge, simply because there is more research on the topic.
  • A red light therapy dose of up to 60 Joules seems to work best. Studies in the low hundreds of Joules often show negative effects so don't overdose.
  • Any high-powered panel on the market will do well for you as a red light therapy panel for workouts. For the best results, check the Shopping Tool and consider products with a lot of 810nm light coming from it. Higher-powered panels will probably also work better because it will penetrate deeper. 

Introduction: The Eternal Search For Obtaining A Workout Performance Edge

The history of trying to find an edge in workout performance is as old as written history (12). Milo of Croton, a famous Greek athlete, carried a young calf on his back while it was growing to enhance his workout performance in the 500 BCE era. Later, Aristotle let his philosophers in training wrestle to not only cultivate the mind but also the body.

Today, it's extremely popular to use many different recovery enhancement techniques, such as taking ashwagandha and zinc to increase testosterone, cold baths for recovery, and creatine supplementation (34567891011121314). Some of these strategies work and others don't. Time is often needed to weed out the truly working strategies from the ones that don't work - despite assumptions that strategies are working. Research now shows that cold or ice baths might be counterproductive or just work equally well as active recovery, counteracting what many people intuitively assume about the post-workout method.

So, for red light therapy before or after workout, I'll have to look at the currently published research to make a determination. Fortunately, quite some research is available on red light therapy for workout performance.

I will have to say that not all this research uses gym workouts. Instead, red light therapy has been tested for many different sports outcomes. I'll include all of that research in this blog post, so I won't limit myself to traditional gym workouts. I think that conclusion is common-sense. While Alex and I love the gym, 90% of the population is different so it's only natural to include studies that pertain to sports in general.

Also, in the next section, I'll first break down studies on red light therapy before or after workouts in general. After that, I'll draw a conclusion from these studies. You don't necessarily need to agree with my conclusion but hopefully, you see that my display of these individual studies is decent. I've included both animal and human studies in this process. I'll draw conclusions based upon both, and if they diverge in terms of outcomes, I'll mention that in my eventual analysis.

So let's get started and explore the research on red light therapy for recovery and workout performance: 

15 Studies Considering Workout Performance And Red Light Therapy Directly

In this section, I'll display all the studies investigating the effects of red light therapy before or after workout. I'll only draw overall conclusions based on this research in a next section. So if you don't want to read my analysis of all these individual studies, skip ahead to that next section. 

f you do want to see my viewpoint of all the data, then continue reading below. I've selected 15 random studies and looked at the overall evidence in these studies to observe what pattern I can see in the data. In a later section, I've looked at systematic reviews on this topic and included their conclusions in my work. 

But first, let's look at 15 different studies on workout performance and red light therapy:

Study 1: Red Light Therapy Before Or After Plyometric Exercise In Humans: Less Soreness And More Muscle Quality

The first study investigates the effects of red light therapy before or after plyometric exercise (15).

The main conclusion of the study is that muscle soreness is reduced and muscle quality increased.

The setup of the study is quite smart: red light therapy (LLLT) was applied either before or after a plyometric workout. Plyometrics are bodyweight exercises that aim to improve power and speed (1617). 

Three outcomes were measured in total: 1) an echo of muscle tissue that establishes the quality of the tissue; 2) muscle soreness, measured with the "Visual Analogue Scale" (VAS) - a 1-10 scale that gives a subjective assessment of pain; 3) maximum contraction of the muscles of the quadriceps, located at the front of the upper leg.

Among these three outcomes, the first and second domains improved. No effect was found in the domain of strength, although, measurements were only taken up to three days after the workout.

Overall, this study hints at the first benefit of using red light therapy before or after workout. The protocol was as follows, which is important for the eventual conclusion I will draw from all this data:

"Placebo and LLLT (810 nm, 200 mW per diode, 6 J per diode, 240 J per leg) were randomly applied on right/left knee extensor muscles of each volunteer before/after a plyometric exercise protocol." (15).

 So, 810nm did the job here. Let's move to the next study:

Study 2: Biomarkers In Elderly Rats After Aerobic Exercise: Red Light Therapy Helps Inflammatory Biomarkers

Next up, we have an animal model study (18). In total, 24 aged rats are included in the study, and 6 young ones. Here's the described study setup:

"The older animals were randomly divided into four groups designated as follows: aged-control, aged-exercise, aged-LLLT, aged-LLLT/exercise group, and young-control animals. Aerobic capacity (VO2max) was analyzed before and after training period. The aged-exercise and aged-LLLT/exercise groups were trained for 6 weeks. LLLT laser was applied before each training session with 808 nm and 4 J of energy to the indicated groups throughout training. The rats were euthanized, and muscle tissue and serum were collected for muscle cross-sectional area and IL-6 and TNF-α protein analysis." (18)

So, some groups received exercise and some didn't, and some groups received red light therapy (LLLT) and others didn't. Red light at 808nm (once again, close to the previous 810nm) was applied. Then, at the end of the study, the unfortunate animals were sacrificed for research. Finally, here's the outcome for the poor animals:

"Levels of IL-6 and TNF-α for the aged-exercise and the aged-LLLT/exercise groups were significantly decreased compared to the aged-control group (p < 0.05). Analysis of the transverse section of the gastrocnemius muscle showed a significant difference between the aged-exercise and aged-LLLT/exercise groups (p < 0.001). These results suggest that laser therapy in conjunction with aerobic training may provide a therapeutic approach for reducing the inflammatory markers (IL-6 and TNF-α), however, LLLT without exercise was not able to improve physical performance of aged rats." (18)

So, overall, inflammatory biomarkers improved but physical performance didn't increase in elderly rats. Let's move on to another human study:

Study 3: Biceps Performance In Humans: Lower Lactate, Lower Inflammation, Greater Endurance

Next up, we have another study investigating humans (19). The simple study setup was quite nice:

"Nine healthy male volleyball players participated in the study. They received either active LLLT (cluster probe with 5 laser diodes; lambda = 810 nm; 200 mW power output; 30 seconds of irradiation, applied in 2 locations over the biceps of the nondominant arm; 60 J of total energy) or placebo LLLT using an identical cluster probe. The intervention or placebo were applied 3 minutes before the performance of exercise. All subjects performed voluntary elbow flexion repetitions with a workload of 75% of their maximal voluntary contraction force until exhaustion." (19)

Surprisingly, the 810nm wavelength was used once again. Also, surprisingly, the power output was 200 mW/cm2 (my interpretation), which is much higher than the generally advertized and overestimated 100 mW/cm2 that many consider a maximum. I considered myself mistaken so I read the full study and found the following:

"Power density 5.495 W/cm2 (for each laser spot) [5 lasers are used in total]

Energy density: 164.85 J/cm2 (for each laser spot)" (20)

So, compared to the dosage you're getting from regular red light therapy panels there's an extremely high dosage used at certain spots in this study. The study used lasers from THOR laser medicine, which we hold in the highest regard on this website (21).

The most important conclusion? Endurance of your biceps muscles (and probably other muscles) can be increased by using red light therapy. And, inflammation levels and lactate (the pump) that are measured in the blood decrease through red light therapy.

A very promising outcome. The total dose applied was only 6 J though, so that's low. The most interesting observation here is that an extremely high local treatment does lead to positive generalized effects (in the biceps muscle in general) when the overall dose isn't too high. 

Moving on to the next study:

Study 4: Increased Quadriceps Performance In Humans After LLLT

Another study using red light therapy in the 800nm range - this time 830nm (22). The study stems from 2014 and was carried out by our excellent Brazilian peers who have published a huge bulk of the LLLT science. The researchers divided 27 soccer players into three groups. Lasers were used, not LEDs - the case can be made that in general, not specific cases, LEDs do equally well as lasers (23).

So here's the study setup according to our Brazilian peers:

"The experiment was performed in two sessions, with a 1 week interval between them. Subjects performed two sessions of stretching followed by blood collection (measurement of lactate and CK) at baseline and after fatigue of the quadriceps by leg extension. LLLT was applied to the femoral quadriceps muscle using an infrared laser device (830 nm), 0.0028 cm(2) beam area, six 60 mW diodes, energy of 0.6 J per diode (total energy to each limb 25.2 J (50.4 J total), energy density 214.28 J/cm(2), 21.42 W/cm(2) power density, 70 sec per leg. We measured the time to fatigue and number and maximum load (RM) of repetitions tolerated. Number of repetitions and time until fatigue were primary outcomes, secondary outcomes included serum lactate levels (measured before and 5, 10, and 15 min after exercise), and CK levels (measured before and 5 min after exercise)" (22).

Put simply, 830nm light was applied to the quadriceps for the intervention groups. Then, all groups had their time to fatigue (exhaustion) and maximum performance was measured. Also, from the blood, the lactate and Creatine-Kinase (CK) levels were measured - CK is one of the most important biomarkers for measuring inflammation.

Overall, a great outcome supporting red light therapy for workout recovery and performance. The conclusion of the paper states that the post-workout group had slightly improved results.

Moving to the next study:

Study 5: Grip Strength And Overall Physiology In Rats

Once more, another rat study (23). I'm still amazed at the opportunities of this animal-based research, even though I consider it just slightly immoral too. But, as humans we don't have any other options, right? So here's the deal of this study:

"A total of 64 male Wistar rats were divided into eight groups: control, control LLLT, control exercise, control LLLT and exercise, arthritis, arthritis LLLT, arthritis exercise, and arthritis LLLT and exercise groups. The experimental RA was induced by a complete Freund's adjuvant injection into the knee joint cavity. Climbing exercises and LLLT (660 nm; 5 J/cm2 per point) were performed as the treatment. In addition, muscle strength was evaluated using the grip strength test, and morphometric evaluations were performed on the ankle joint." (23).

 "RA", here, stands for Rheumatoid Arthritis - an inflammatory autoimmune disease that affects the joints (242526). Joints become deformed, painful, and swollen, and the ability of muscles around the joint to perform goes down.

Overall, red light therapy restored muscle power and the negative morphological aspects of RA. Both exercise and red light therapy were helpful, generally, which hints at an interesting outcome.

More than 10 years ago, when I was working as a physical therapist, I'd often use passive and active exercise for patients with RA. Fortunately, it does seem that red light therapy can play an important role here as well. But there's an important question though:

Why bother about this outcome if you're healthy? Well many other studies show benefits for young animals and people too:

Study 6: Rats Show An Increase In VO2 Max Using Red Light

Another rat study from the Brazilian research team that I talked about earlier (27). Once more, this is a rat study. The study outcome was inflammation, which in turn, affects VO2 max, an extremely helpful biomarker of your body's overall oxygen-carrying and usage capacity (282930). The extremely well-written abstract of the study states the following:

"Thirty Wistar rats (Norvegicus albinus) (24 aged and six young) were tested. The older animals were randomly divided into aged-control, aged-exercise, aged-LLLT, aged-LLLT/exercise, and young-control. Aerobic capacity (VO2max(0.75)) was analyzed before and after the training period. The exercise groups were trained for 6 weeks, and the LLLT was applied at 808 nm and 4 J energy. The rats were euthanized, and muscle tissue was collected to analyze the index of lipid peroxidation thiobarbituric acid reactive substances (TBARS), glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) activities. VO2 (0.75)max values in the aged-LLLT/exercise group were significantly higher from those in the baseline older group (p <0.01) and the LLLT and exercise group (p <0.05). The results indicate that the activities of CAT, SOD, and GPx were higher and statistically significant (p <0.05) in the LLLT/exercise group than those in the LLLT and exercise groups. Young animals presented lesser and statistically significant activities of antioxidant enzymes compared to the aged group. The LLLT/exercise group and the LLLT and exercise group could also mitigate the concentration of TBARS (p > 0.05). Laser therapy in conjunction with aerobic training may reduce oxidative stress, as well as increase VO2 (0.75)max, indicating that an aerobic exercise such as swimming increases speed and improves performance in aged animals treated with LLLT."

Normally I don't quote such large sections but there's no way I could have written this better. Overall, the combination of red light therapy and exercise does best, not either option. Again, the now almost famous ~810nm light was used - not the 850nm used in many red light therapy panels.

Next up:

Study 7: Muscle Thickness And Strength In Male Human Participants

Another great study, this time, fortunately using human study participants - males to be exact (31). The participants were divided into three groups: 1) control (no exercise or red light therapy); 2) exercise but no red light therapy; 3) exercise and red light therapy. Red light therapy was used on the knee extensor muscle at front of the leg, called the "quadriceps". The exercise groups of participants then trained for 8 weeks in total. Red light therapy was applied before each training session in the third group.

The outcome is highly promising:

"[The Control Group] presented no changes in any variable throughout the study, while eccentric training led to significant increases in muscle thickness and peak torque in [Training Group] and [Training and Light Therapy Group]. Subjects from [Training And Light Therapy Group] reached significantly higher percent changes compared to subjects from [Training Group] for sum of muscles' thicknesses (15.4 vs. 9.4%), isometric peak torque (20.5 vs. 13.7%), and eccentric peak torque (32.2 vs. 20.0%).

So here's why that outcome matters: there's at least a 50% greater increase in muscle thickness, and about 60% increase in peak torque. While I'm oversimplifying the concept or "torque", for your understanding it simply means that the participants in the red light therapy group got stronger (32).

Moving on:

Study 8: LEDs And Lasers Pre-Exercise In Human Participants

Next up, another study using human participants (33). Both LEDs and lasers were used. The wavelengths included were 670nm, 875nm, and 905nm. Once again, that light was applied to the quadriceps muscle of the upper leg. The participants then engaged in what is called a "Maximum Voluntary Contraction" (MVC) - basically training their upper leg muscles as hard as they can. After the workout, the amount of muscle soreness (DOMS) and inflammatory markers were measured. Also, different doses as measured in Joules were used in the red light therapy dosing.

The outcome of the study was as follows:

"Phototherapy increased (p < 0.05) MVC was compared to placebo from immediately after to 96 h after exercise with 10 or 30 J doses (better results with 30 J dose). DOMS was significantly decreased compared to placebo (p < 0.05) with 30 J dose from 24 to 96 h after exercise, and with 50 J dose from immediately after to 96 h after exercise. CK activity was significantly decreased (p < 0.05) compared to placebo with all phototherapy doses from 1 to 96 h after exercise (except for 50 J dose at 96 h). Pre-exercise phototherapy with combination of low-level laser and LEDs, mainly with 30 J dose, significantly increases performance, decreases DOMS, and improves biochemical marker related to skeletal muscle damage." (33)

So, in plain English, red light therapy works at 670 and the high 800 low 900nm range for increasing exercise performance, lower soreness, and decreasing inflammatory biomarkers. Another win for red light therapy. 

Study 9: Fatigue And Muscle Damage In Judo Athletes Who Received Red Light Therapy Before Their Workout

Fortunately, there's one more human study I came across (34). Sixteen judo players were randomized by limp, meaning that one of their limbs randomly received red light therapy and the other limb didn't. The players then used a "stretch-shortening" session to induce muscle damage and fatigue. Later on, the jumping ability, an echo scan of the quadriceps muscles, and muscle soreness were measured, before, during, and after the workout.

The researchers conclude the following:

"No differences were observed between photobiomodulation therapy and placebo at any time points for any variables (p > 0.05), indicating no positive effect favoring photobiomodulation therapy. In conclusion, our findings suggest no effect of photobiomodulation therapy applied before exercise to reduce lower limb muscle fatigue and damage during and following a stretch-shortening cycle protocol in judo athletes." (34).

So, this was the first study I came across that didn't have a positive outcome.

The full study describes that both lasers and LEDs were used in the 600, 800, and 900nm range (35). The researches speculate in the full text of the study why there might not be a positive outcome, giving reasons such as the nature of the participants or the dosing protocol. I won't include their thought process here as you can read that data yourself by clicking the link - I just wanted to say that it's not crystal clear why some studies have positive outcomes while others do not. Even the researchers speculate why no outcome was found.

Next up:

Study 10: Different Doses For Running Performance And Recovery On A Treadmill

The following study is extremely interesting because an LED panel is used with 660nm and 850nm (36). That outcome is interesting as many panels such as the Red Light Rising Advantage 900 and the Joovv Solo 3.0 use that wavelength setup. The human participants did a maximum treadmill test. Before that test, they either received placebo, a 30J dose, 120J or 180J per area. The back of the upper legs (hamstrings), the aforementioned quadriceps, and the biggest calf muscle (gastrocnemius) were treated in the person receiving the light treatment.

The near-infrared part of the equation was slightly higher powered, as the researchers write:

"The LED was applied using an equipment with 56 diodes of red light (660 nm; 50 mW/cm2 and 1.5 J/cm2 each diode) and 48 diodes of infrared light (850 nm; 150 mW/cm2 and 4.5 J/cm2 each diode)." (36)

The end result, here, was once more that no effect was found. Maximum running speed, lactate (how well your body processes the pump), heart rate during exercise, and the participant's perception of exhaustion were all similar across all groups.

Unfortunately, once more a study showing no effect from red light therapy.

Study 11: 660nm Light Superior For Training Wrist Function In Human Participants

Then, there's a more recent 2020 study using a light setup that's very similar to what different red light therapy panels already emit: 660nm and 830nm this time (37). Interestingly enough, blood flow restriction training was used as well, which Alex is currently testing. 

Here's the setup of the groups:

  • Group 1: normal strength training
  • Group 2: blood flow-restricted training
  • Group 3: blood flow-restricted training and 660nm light at an 18.9J energy dose
  • Group 4: blood flow-restricted training and 830nm light at a 17.2J energy dose

The 660nm group performed best overall, and their gains exceeded the 830nm group in terms of grip strength and wrist extensor strength. The wrist extensors are the muscles opposing the flexors - the flexors are activated when you grip an object. Also, the researchers tested for the electromyographic behavior and the 660nm group did best here as well, better than 830nm. With electromyographic behavior, the electrical potential of muscles to be activated by nerves is tested.

One more win for red light therapy, showing that 660nm light is useful for performance. Unfortunately, I didn't have access to the full text of the study so I couldn't read how the light was exactly applied and how long the study lasted.


Study 12: Running Performance In High-Level Soccer Players With 810nm Before A Treadmill Test

Another running test, this time in high-level soccer players (38). 810nm light was used. The soccer players either received the red light therapy or a placebo intervention (which looks real) and then ran to exhaustion on a treadmill. Next up, in the abstract of the study, the researchers describe the extremely intricate amount of biomarkers that they measured during this process:

"We analyzed rates of oxygen uptake (VO2 max), time until exhaustion, and aerobic and anaerobic threshold during the intense progressive running test. Creatine kinase (CK) and lactate dehydrogenase (LDH) activities, levels of interleukin-1β (IL-1-β), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α), levels of thiobarbituric acid (TBARS) and carbonylated proteins, and catalase (CAT) and superoxide dismutase (SOD) activities were measured before and five minutes after the end of the test. PBMT increased the VO2 max (both relative and absolute values-p < 0.0467 and p < 0.0013, respectively), time until exhaustion (p < 0.0043), time (p < 0.0007) and volume (p < 0.0355) in which anaerobic threshold happened, and volume in which aerobic threshold happened (p < 0.0068). Moreover, PBMT decreased CK (p < 0.0001) and LDH (p < 0.0001) activities. Regarding the cytokines, PBMT decreased only IL-6 (p < 0.0001). Finally, PBMT decreased TBARS (p < 0.0001) and carbonylated protein levels (p < 0.01) and increased SOD (p < 0.0001)and CAT (p < 0.0001) activities." (38).

Translated to plain English, red light therapy affects workout performance on many different levels. VO2 max, your overall oxygen carrying capacity up until your cells, increases. Also, the time until exhaustion when running and the time you can perform anaerobically (without using oxygen yet) increases. Markers of metabolic damage and/or end products of metabolic processes also improve.

The conclusion of this study is that red light therapy doesn't just improve performance, but also reduces metabolic waste and oxidative stress after workouts, thereby enhancing recovery.

Then there's study 13:

Study 13: Red Light Therapy After Workouts' Effect On Performance And Inflammation In Water Polo Players 

Another human study, from 2016 this time, researching the effects on water polo players and workout performance and inflammation (39). Part of the research participants received a sham intervention while others got real red light therapy. LIght at 810nm was used. The red light therapy was applied for 5 days straight, immediately after each training session. The light was applied to the adductor muscles, which are located around the inner tight of the upper leg.

Participants did a 200m sprint in the pool and a 30-second "crossbar jump test" before training. Blood samples were also taken for biomakers. Here's the outcome of the study:

"There was no significant change in the P200 exercise in the LLLT group compared with the placebo group but there was a moderate improvement in the 30CJ (8.7 ± 2.6 %). IL-1β and tumor necrosis factor-alpha presented increased (P < 0.016) concentration within group 48 h after the last LLLT intervention compared to pre, 0, and 24 h, but did not differ between groups. IL-10 increased over time in the placebo group and reached a moderate effect compared to the LLLT group. The creatine kinase decreased significantly (P = 0.049) over the time within the LLLT treatment group, but there was no significant change in lactate dehydrogenase (P = 0.150). In conclusion, LLLT resulted in a non-significant, but small to moderate effect on inflammatory and muscle damage markers and a moderate effect on performance in water polo players" (39).

So, there's an effect on performance, but not on the 200m sprint. And, with regard to muscle damage, the outcome of the 810nm red light therapy group was superior to the placebo intervention. Overall, this research demonstrates another slight edge for red light therapy over placebo.

Interesting, also, is that light therapy was applied after the workout in this study. I'll keep that fact in mind when I try to formulate my conclusion based on these 15 studies. Right now, we're arriving almost at the last study:

Study 14: Anti-Inflammatory Painkillers And Red Light Therapy For Muscle Damage In Rats

This 2016 study investigates rats that have muscle damage induced in them (4041). The goal here, was to investigate whether red light therapy can be a helpful alternative to a class of anti-inflammatory painkillers called "NSAIDs". These painkillers don't work so well according to the research, for muscle injuries, and have side-effects.

Researchers induced an injury to the "tibialis anterior" muscle, which is located at the front of the shin. Next up, the researchers used the following complicated protocol:

"After 1 h, rats were treated with PBMT (830 nm, continuous mode, 100 mW of power, 35.71 W/cm2; 1, 3, and 9 J; 10, 30, and 90 s) or diclofenac sodium (1 g). Our results demonstrated that PBMT, 1 J (35.7 J/cm2), 3 J (107.1 J/cm2), and 9 J (321.4 J/cm2) reduced the expression of tumor necrosis factor alpha (TNF-α) and cyclooxygenase-2 (COX-2) genes at all assessed times as compared to the injury and diclofenac groups (p < 0.05). The diclofenac group showed reduced levels of COX-2 only in relation to the injury group (p < 0.05). COX-2 protein expression remained unchanged with all therapies except with PBMT at a 3-J dose at 12 h (p < 0.05 compared to the injury group). In addition, PBMT (1, 3, and 9 J) effectively reduced levels of cytokines TNF-α, interleukin (IL)-1β, and IL-6 at all assessed times as compared to the injury and diclofenac groups (p < 0.05). " (40).

So, different power outputs using 830nm light ware used. The anti-inflammatory effects of the red light therapy was similar to the effects of topically-applied NSAIDs. The 3J dose group seems to have the best overall outcome here. In another publication on the same study, the researchers publish their data on the outcomes in the cells. The rats were investigated 6, 12, and 24 hours after the injury. The researchers found the following:

"[T]he 9 J (321.4 J/cm2) dose was the most effective in organizing muscle fibers and cell nuclei. On the other hand, the use of diclofenac sodium produced only a slight improvement in morphological changes. Moreover, we observed a statistically significant increase of muscle work in the PBMT 3 J (107.1 J/cm2) group in relation to the injury group and the diclofenac group (p < 0.05). The results of the present study indicate that PBMT, with a dose of 3 J (107.1 J/cm2), is more effective than the other doses of PBMT tested and NSAIDs for topical use as a means to improve morphological and functional alterations due to muscle injury from contusion." (41).

Overall, the 3J dose has the best outcome once more. The overall conclusion here is that red light therapy can compete with NSAIDs when consider recovery from a muscle injury, and is superior in some areas, especially given the absence of side-effects.

Finally, moving on to the last study:

Study 15: Lasers For Muscle Performance During Exercise

So, now to make things even more complicated, a study investigating red light therapy during a workout (42). Young men either received an 808nm laser treatment or a sham intervention. There was a crossover too, so all participants received the same intervention. The training setup was as follows:

"The training sessions consisted of three sets of 20 RM of knee flexion-extensions using an isokinetic dynamometer at 60 degrees/sec plus LLLT (808 nm, 100 mW, 4 J), or placebo, applied to quadriceps femoris muscles between sets, and after the last series of this exercise. After 1 week (washout period), all volunteers were exchanged among groups and then all assessments were repeated." (42).

So, between the 20 Repetition Max (RM) sets and after the last set, the intervention participants received the 808nm 4J treatment. 

Red light therapy appeared successful for improving the Repetition Max, and led to improvements as measured on the "electromyography fatigue index". So, here we learn that red light therapy during exercise can be helpful too, and after the last set of repetitions.

Unfortunately, this outcome further complicates this topic, as the original question pertained to whether red light therapy before or after workout sessions was better. To get a better understanding of this entire field of study - I've therefore referred to a few systematic reviews and checked the conclusions that they got from often greater amounts of data than I included:

Outcomes Of Existing Systematic Reviews On Red Light Therapy Before Or After Workout

In this section below, I'll briefly consider a few systematic reviews on red light therapy for sports performance (43). I'll consider these studies one by one.

First, a review from 2021, so extremely recent (43). The review, just as the studies I went through earlier, concludes that there is an effect of red light therapy for sports performance. Both training and results during competition are supported by red light therapy. However, the researchers also state that many questions still remain regarding how to best use red light therapy:

"The biggest questions about PBM applied in sports are still open, as follows [..]:"Optimal wavelengths, optimal time, before or after, or both, and at what interval of physical activity?Optimal PBM parameters (power density, fluency, modulation frequency)?The number of points for each muscle?The interaction of PBM with muscles and the chain of biochemical reactions triggered inside cells and ultimately reflected in increased performance in sports?Considering the notorious biphasic dose response, typical of PBM and its interaction with muscles, i.e., could it be managed, controlled or achieved without great difficulty to apply exactly as much energy as we need and not too much irradiation?Is it right to combine different light sources, i.e., both lasers and LEDs?" (43)

Basically, these are the common sense questions. For instance, Alex hints at many of these issues in his YouTube videos where he talks about his 5+ years of experience with red light therapy, and a video about how to use red light therapy. Here, Alex talks about how he doesn't know the exact wavelengths that are best for all different goals, exactly what the best dosage in Joules is for each situation, how often you should use red light therapy, and whether lasers or LEDs are best.

Reading through the systematic review, I got the same impression.

The bottom line is this: red light therapy works. But, there's no exact standardized protocol that's universally valid for everyone. An even bigger problem is that athletes are different from each other - not everyone has the same genetics and the same mitochondria and same lifestyle, so expecting there to be a universal protocol that works best for everyone is incorrect in my opinion.

Future studies will need to be more standardized, or at least develop standardized protocols. Right now, the publications are extremely diverse in the parameters they used, such as wavelengths, treatment time, LEDs versus lasers, and so forth.

Nevertheless, the systematic review I referred to does state that a maximum dose of 60 J is best (43). 10J is a good minimum dose, at least before a workout. For more information on that topic, check my guide on red light therapy dosing. There's also a decent amount of research on LEDs now, not just lasers, and the LEDs seem to be working well. High-powered lasers, on the contrary, appear to be riskier, especially in elite athletes. Research with red light therapy beds - which cover the entire body - is also just beginning.

Overall, you hopefully see that the topic is extremely complex. From the top of my head, I can easily find many different domains of human physiology that are affected, such as:

  1. Enhanced mitochondrial efficiency
  2. Better blood flow
  3. Quicker injury recovery
  4. Greater bone density
  5. An easier time building muscle and burning body fat
  6. Less muscle soreness
  7. Impeding (chronic) pain
  8. Quicker injury healing
  9. Improved well-being
  10. Higher sleep quality
  11. Increased collagen synthesis
  12. Better cognitive function

Now, imagine that all of these variables interact with each other, while (in)directly affecting sports and workout performance too. 

So now let's look at two other red light therapy reviews and consider what they say (4445).

The first of these included 46 independent studies on the topics of human muscle tissue and red light therapy (44).

Here, the first thing I notice is that almost all of the studies are contact red light therapy studies, meaning that the lasers or LEDs are placed against the skin. GembaRed has extensively talked about the contact versus non-contact method of red light therapy in the past. Basically, what it comes down to, is that if you use a distance such as 3 or 6 inches, you'll need a higher power output as some of the light is reflected off the skin. Skin reflection of light is prevented when you're placing LEDs directly on the skin.

Interestingly enough, after going through 46 scientific articles meticulously, this systematic review (which integrates existing studies into a new whole) also states the following, just as the previous systematic review did:

"What is (are) the best wavelength(s) to use?When is the best time to apply PBM on muscles? Before or after exercise? If before or after exercise, how long should the time interval between light and exercise be?What are the best PBM parameters (irradiance, fluence, pulse structure)?How many points or sites of irradiation should be used on each muscle group?How exactly does PBM interact with muscle tissue on a biochemical level to increase sports performance?Does the well-known biphasic dose response that is typical of PBM apply to muscles? In other words is it possible to use too much light?" (44)

So, in a sense, we're back at square one!

Also, the review concludes that right now, given the science, the most important wavelengths for muscle performance are found in the 630-660nm range and the 808-950nm range. Near-infrared also generally works better due to its deeper penetration.

However, the researchers say that it's also important to use both red and near-infrared at the same time. But, overall, a big proportion of near-infrared probably works best.

Combining both parts of the light spectrum probably gives advantages from a mitochondrial perspective. 

What's extremely interesting, moreover, is that the study states that the best time to use red light therapy before exercise is 3-6 hours earlier, NOT 5 minutes before a workout.  There's little research on this topic though, but at least two studies show the superiority of this protocol (4647). Muscle damage is prevented by that protocol and muscle performance increases.

Then, there's the possibility to use red light therapy post-workout. The researchers write:

"The second strategy is to apply PBM using LLLT or LEDT immediately after each bout of exercise in order to accelerate muscle recovery [...]. This strategy appears to be especially effective when used in combination with regular exercise training programs that can last for days or even weeks [...]. In addition, the use of PBM after each session training of exercise training programs also seems to increase the potential gains of performance, including defense against oxidative stress, muscle cell proliferation, energy muscle content (glycogen and ATP) and mitochondrial metabolism [...], in addition to several other effects reported previously (see review [...). However, this issue is not completely clear in the literature, since a recent study reported better results in favor of muscular pre-conditioning in training programs [...]. We believe that further investigations to answer this question in are necessary."

So, right now, there might be a slight benefit to pre-workout usage of red light therapy compared to post-workout. But once again, there's the problem of the variation between treatment protocols that makes drawing conclusions extremely difficult. Nevertheless, in the end, the conclusion is that red light therapy works and that there are far more positive than negative (non-working) outcomes.

Next up, let's move to another systematic review (45). 

That review also gives a slight preference to near-infrared over red light, in part because it has been studied in more detail. Once more, the researchers note the absence of consensus on dosing parameters. 

The main mechanisms noted to be affected by red light therapy are mitochondrial dynamics once again, and oxidative stress, repair of muscle damage (in case of injuries), gene expression, motor unit recruitment, and metabolic benefits. These domains are then treated into extreme detail, and somewhat beyond my understanding despite me having a degree in physical therapy.

Overall, this systematic review is positive but doesn't yield any specific guidance for red light therapy sessions except to state that the topic is extremely complicated. 

And, after checking these three systematic reviews, let's consider my opinion on all of these outcomes below: 

Assessment Of The Outcome Of The Red Light Therapy Studies & Systematic Reviews

Fortunately, the outcome of the studies I analyzed myself and the systematic reviews align decently. As already stated in the summary, I think you can draw a few conclusions based on this research so far, such as:

  • Generally, red light therapy before or after workout works. There's a slight advantage to using red light therapy before workouts, and, there's very little research on using red light therapy during workouts, such as during rest.
  • If you use red light therapy before a workout, it's best to do so 3-6 hours before a workout, given the current evidence. Of course, this pattern might change in the future once we understand all these principles better through more publications in this field.
  • Near-infrared wavelengths are slightly more important. There are not many comparison studies between red and near-infrared either, usually, they are combined in studies (so red + NIR) but as far as I know, there are no studies with either red, NIR, or red + NIR. And, as most studies have used near-infrared, we can probably conclude that given the research right now, and due to its potential deeper penetration, panels with a higher percentage of infrared have a slight advantage.
  • Nobody knows the "universally perfect protocol" for red light therapy before or after workout. It's best to use common sense and my red light therapy dosing guide with dosages of up to 60 Joules. Also, check Alex's "how to use red light therapy" guide on YouTube for more information on implementing a common-sense approach.
  • There are an extreme amount of biological mechanisms through which red light therapy works for workout performance. These include anything from upgrading mitochondrial efficiency to stimulating blood flow and decreasing muscle damage. Many of these mechanisms are probably undiscovered also, so, in the future, this topic will probably become even more complex.
  • As a result, there are a huge number of benefits using red light therapy before or after a workout. I've listed these benefits in the section of systematic review above, and these include less muscle soreness and pain, higher mitochondrial efficiency and function, greater gains in muscle, endurance and strength in workouts over time, enhanced bone density, and so forth. 
  • Almost always, combining red light therapy with working out works best. So you're getting inferior results if you just use red light therapy or just work out.
  • Many of the studies use the contact method for delivering the red light therapy, and, more laser studies are present than LED studies. Fortunately, more and more LED studies are being published and these are also positive, which supports the claim that LEDs are effective too, not just lasers as many in the LLLT field sometimes assume. The only thing I might disagree with with other gurus in the space is that a 20mW/cm2 dose is necessarily optimal, as laser studies precisely use higher dosages often and work well.
  • Overall, more human studies are needed too. This is almost always the case, and with this topic it's no different.
  • Also, lastly, I want to say that my methodology isn't perfect. I don't have endless hours to go through all individual studies myself and to properly go through 50-100+ studies published on this topic, you'd probably need a month or two worth of time to do so if you want to avoid all mistakes. In that case, you'd have to read through every single full text of every study, get the main parameters out of each study, and critically analyze all the results of every single study. Also, this undertaking could have been made far more complex if you also included all the studies on the biological mechanisms, such as pain, sleep quality, bone density, and so forth.
  • Other Strategies To Enhance Workout Recovery? By no means do I ever want to suggest that by using red light therapy alone, your recovery will be perfect. Instead, red light therapy is just one tool in a big toolbox. Yes, using red light therapy before or after workout sessions will have a positive effect. But, many other strategies work, as I already alluded to in the introduction of this blog post.

Lastly, let's have a look at which panels I recommend for before or after workout red light therapy based on my research: 

Best Red Light Therapy Before Or After Workout Devices

So I've removed the 2023 version of what was written here to make the content more evergreen. What I now recommend is to check our red light therapy shopping tool for panels that have high power and lots of 810nm light.

The reason why I don't give specific recommendations for a panel or product is because new products emerge on the market every day. So instead of telling you what to buy, I give guidelines.

What also might be helpful is to watch Alex's best red light therapy panel 2024. You can see the video here:

The video contains a section about the panels that have the most power and also about 810nm light that you'd want to have given the current science. Here's the extended cut of that same video:

Those videos should help you find a high-powered 810nm-dominant panel for sure!

Finishing Thoughts: Common Sense Still Rules

I'm very happy with the outcome of this blog post about red light therapy before or after workout. The simple conclusion is that you'll have to use a normal dose of up to 60 J, 3-6 hours before training, which includes infrared light, for the best results. And, by no means is just the 850nm near-infrared wavelength valid - 808, 810, and 830 probably appear more frequently than the famous 850nm wavelength.

Hopefully, in the future, I can update this blog when more systematic reviews come out, or, in some way go through all the studies available right now, even though that is enormously time-consuming. I hope you find lots of benefit from reading through this blog, and, even though it doesn't contain all the final answers to the secret of the universe, you hopefully can give more context to what is known and what is currently unknown. Thereby you reduce the amount of guessing in the process.

Items Mentioned:

This is a post by Bart Wolbers. Bart finished degrees in Physical Therapy (B), Philosophy (BA and MA), Philosophy of Science and Technology (MS - with distinction), and Clinical Health Science (MS), has had training in functional medicine, and is currently chief science writer at Lighttherapyinsiders.com

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