If you use red light therapy as part of your fitness or recovery routine, you may have wondered when you should actually use it: before your workout or after?
It’s a good question because red light therapy, also known as photobiomodulation (PBM), has been studied both as a way to prepare muscles for exercise and as a recovery tool afterwards.
The good news is that you don't necessarily have to choose one. Research suggests that both pre- and post-exercise red light therapy may have benefits, although the potential benefits can differ depending on when you use it and what you're trying to achieve.
So, Red Light Therapy Before or After Exercise: Which Is Better?
If your priority is exercise performance and preparing your muscles, using red light therapy before exercise may have an advantage. If your priority is reducing post-workout soreness and supporting recovery, using it after exercise may be more appropriate.
Let's take a closer look at what the research says.
Red Light Therapy Before Exercise
Using red light therapy before a workout is sometimes described as pre-exercise photobiomodulation.
The idea is to expose the muscles to red or near-infrared light before exercise rather than waiting until soreness or fatigue has already developed.
Research suggests there may be a benefit here.
A 2024 meta-analysis of 34 randomised controlled trials found that photobiomodulation was associated with improvements in muscle endurance and recovery of muscle strength. The researchers also found that pre-exercise application improved muscle endurance and recovery outcomes in some groups, although results varied depending on participants' activity levels.
Earlier systematic reviews have also found promising results from applying phototherapy before exercise, although researchers have highlighted significant differences between studies in terms of wavelengths, doses, treatment duration and exercise protocols.
Potential benefits of using red light therapy before a workout
Depending on the individual and the treatment protocol, pre-workout red light therapy may help support:
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Muscle endurance
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Muscle function
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Exercise performance
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Recovery of strength following exercise
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The body's response to exercise-induced muscle stress
This doesn't mean that using red light therapy before every workout will automatically make you stronger or allow you to train harder.
The research is promising, but results aren't completely consistent, and the exact dose and treatment parameters appear to matter.
Red Light Therapy After Exercise
Post-workout red light therapy takes a slightly different approach.
Instead of preparing the muscles for exercise, the goal is to support the body during the recovery period that follows.
After a demanding workout, it is normal for muscles to experience temporary fatigue, soreness and changes in function. Delayed onset muscle soreness (DOMS) can become particularly noticeable during the following one to three days.
This is where post-exercise photobiomodulation may be useful.
A 2025 systematic review and meta-analysis looking specifically at DOMS found that photomodulation therapy was associated with reduced muscle soreness at 72 and 96 hours after exercise, while muscle strength was improved at 24 and 48 hours in the studies included in the quantitative analysis.
Even more recently, a 2026 meta-analysis of randomised controlled trials examined the effects of photobiomodulation on DOMS and strength following exercise. The researchers found reductions in measures of muscle soreness and improvements in strength across several time points following exercise.
Potential benefits of using red light therapy after a workout
Post-exercise red light therapy may help support:
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Muscle recovery
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Reduction in delayed-onset muscle soreness
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Recovery of muscle strength
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Management of exercise-related muscle discomfort
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The body's response to exercise-induced muscle stress
So, if you're finishing a particularly demanding training session and your main concern is how your muscles will feel over the next couple of days, post-workout red light therapy is a sensible time to consider using it.
So, Is Red Light Therapy Better Before or After Exercise?
This is where things get interesting.
There isn't enough evidence to say that one timing is universally better for everyone.
Instead, the best timing depends on your goal.
| Your goal | When to use red light therapy |
|---|---|
| Support exercise performance | Before exercise |
| Support muscle endurance | Before exercise |
| Prepare muscles for training | Before exercise |
| Reduce post-workout soreness | After exercise |
| Support muscle recovery | After exercise |
| Support recovery between training sessions | After exercise |
| Want to support both performance and recovery | Consider both |
The evidence for pre-exercise use is particularly interesting because several studies have found improvements when photobiomodulation is applied before exercise. Meanwhile, more recent research has also found benefits for soreness and strength recovery following exercise.
What If You Want to Use Red Light Therapy Both Before and After Exercise?
For people who regularly train, there is no reason that red light therapy has to be restricted to one point in the workout cycle.
You could incorporate it into your routine according to your goals.
For example:
Before exercise:
Use red light therapy as part of your preparation before a demanding workout, particularly when your focus is performance or muscle endurance.
After exercise:
Use it as part of your recovery routine when your focus is muscle soreness and getting ready for your next training session.
However, more isn't necessarily better.
Photobiomodulation appears to have a dose-dependent and potentially biphasic response, meaning that increasing exposure indefinitely isn't necessarily going to produce better results. Treatment parameters such as wavelength, irradiance, dose and treatment time can all influence the outcome.
For this reason, it's important to follow the recommended treatment instructions for your particular device rather than assuming that longer sessions will provide greater benefits.
Red Light vs Near-Infrared Light for Exercise
You'll often see red light and near-infrared (NIR) light mentioned together when looking at red light therapy for exercise.
Both fall under the broader category of photobiomodulation, but they have different wavelengths and interact with tissue differently.
Red light is generally used for more superficial tissues, while near-infrared wavelengths can penetrate further into tissue.
This is one reason many devices designed for muscle recovery combine red and near-infrared wavelengths.
If your goal is supporting muscles after exercise, a device that includes appropriate near-infrared wavelengths may be particularly relevant. However, wavelength alone doesn't determine whether a treatment will work. Dose, irradiance, treatment distance, treatment area and treatment time also matter.
How Long Should You Use Red Light Therapy Before or After Exercise?
There isn't one universal session length that applies to every red light therapy device.
The research uses a wide range of treatment parameters, which is one of the biggest challenges when translating scientific studies into everyday use.
Rather than copying the session time from a study and applying it to a completely different device, follow the manufacturer's recommended treatment time and distance.
The goal isn't to spend as much time as possible under the lights. It's to deliver an appropriate dose consistently.
The Bottom Line: Before or After Exercise?
So, should you use red light therapy before or after exercise?
The answer depends on what you're trying to achieve.
Before exercise:
Red light therapy may be useful if you're interested in supporting muscle endurance, exercise performance and the muscle's response to training. Several studies and reviews have found promising results from pre-exercise photobiomodulation.
After exercise:
Red light therapy may be more useful if your priority is recovery, particularly when it comes to muscle soreness and restoring strength following demanding exercise. Recent 2025 and 2026 research provides encouraging evidence in this area.
Want both?
You can incorporate red light therapy into both sides of your training routine, provided you're following the recommended protocol for your device.
Ultimately, red light therapy should be viewed as a complement to a well-rounded training and recovery routine, not a replacement for the fundamentals.
Regular exercise, adequate protein and nutrition, hydration, quality sleep and appropriate rest remain the foundation of recovery.
Red light therapy may simply be another tool you can add to the routine.