Afternoon slumps are so common that many of my clients describe them as “just part of getting older” or “the price of a busy life.” By 2:00 or 3:00 PM, focus fades, muscles feel heavy, and the temptation to reach for another coffee or something sugary is hard to resist. As a red light therapy wellness specialist, I see a different pattern: when we support cellular energy, sleep quality, recovery, and pain levels with the right routines, those afternoon crashes often soften or disappear.
Red light therapy is not magic, and the science is still evolving. But there is a growing body of research suggesting it can support recovery, sleep, and pain relief in ways that can translate into steadier daytime energy. In this article, I will walk you through what the evidence actually says, where the hype is ahead of the science, and how you can build a practical at‑home red light routine to better support your afternoon energy.
Why Afternoon Energy Crashes Happen
Afternoon fatigue rarely has a single cause. In real life, it is usually a mix of short sleep, high stress, blood sugar swings, long hours of sitting, muscle soreness from workouts, and underlying medical issues in some people. Even without a formal diagnosis, strong mid‑day fatigue is often a sign that your body’s recovery systems are struggling to keep up with the demands you place on it.
From a cellular perspective, you can think of afternoon energy crashes as an “energy mismatch.” Your brain and muscles need sustained fuel and oxygen, but your cells may be low on usable energy, your circulation may be sluggish from hours at a desk, and your nervous system may be stuck in stress mode. Red light therapy, also called photobiomodulation, targets precisely those underlying processes: mitochondrial energy production, circulation, and inflammation.
What Red Light Therapy Is (and Is Not)
Many people first hear about red light therapy in the context of anti‑aging facials or hair growth caps. Medically, the term most experts use is photobiomodulation. According to overviews from Cleveland Clinic and WebMD, it involves using low‑level red or near‑infrared light, usually in the range of roughly 630 to 850 nanometers, to stimulate biological processes in the skin and deeper tissues. Devices can be full‑body beds, standing panels, face masks, caps, wands, or smaller pads.
Unlike ultraviolet light, red and near‑infrared light used for this purpose is non‑ionizing. It does not tan or burn the skin and does not carry the same cancer risks as ultraviolet radiation. Stanford Medicine’s dermatology experts emphasize that the risk of serious side effects is low when the light is used properly and not directed into the eyes.
At the same time, it is important to understand what red light therapy is not. It is not a tanning bed. It is not a replacement for sleep, nutrition, or medical care. And, as Stanford Medicine and TrainingPeaks both point out, it is not yet a fully proven performance enhancer for athletes or a cure‑all for every condition advertised online. The strongest evidence is in clinical dermatology for skin and hair, in certain types of pain, and for very specific recovery contexts. Afternoon energy is an emerging, indirect application, not a formally established medical indication.
How Red Light Therapy Works at the Cellular Level
To understand how red light might support afternoon energy, it helps to zoom in to the level of your cells.
Photobiomodulation primarily targets structures in the mitochondria, the “power plants” of your cells. Research summaries from Function Smart Physical Therapy, the Physical Achievement Center, and the National Strength and Conditioning Association describe a common mechanism: red and near‑infrared light is absorbed by a mitochondrial enzyme called cytochrome c oxidase. When that happens, several things appear to occur.
First, mitochondrial ATP production can increase. ATP is the chemical currency your muscles and brain use to do work. Some athletic studies cited by clinics such as Function Smart report up to about a 200 percent increase in cellular energy production in response to specific light doses, although that figure is not universal across all studies.
Second, red light influences nitric oxide and blood flow. Light exposure can promote nitric oxide release and vasodilation, meaning blood vessels widen. Reviews from Cleveland Clinic and University Hospitals note that this improved microcirculation may help deliver more oxygen and nutrients while clearing waste products more efficiently.
Third, red light appears to modulate inflammation and oxidative stress. Sports‑medicine articles from ACE Fitness, Function Smart, and others describe reductions in markers such as C‑reactive protein and creatine kinase in some trials, suggesting better control of exercise‑induced damage. Chronic inflammation and oxidative stress are well‑known drains on long‑term energy.
Put simply, red light therapy is not “stimulation” in the way caffeine is. It is more like giving your cells a better tool kit for producing energy and handling stress. Over time, that cellular support can show up as less soreness, better sleep, and steadier daily energy.
What the Science Actually Shows
Because red light therapy is marketed so aggressively online, I want to separate what has good evidence from what is still speculation.
Recovery, Muscle Fatigue, and Performance
A large body of studies looks at photobiomodulation in athletes and active people. Several clinic‑based articles, including those from Function Smart Physical Therapy, Fick PT & Performance, and the Physical Achievement Center, summarize findings like these:
Researchers using red and near‑infrared wavelengths between about 660 and 850 nanometers have observed increased muscle strength, better endurance capacity, and enhanced power output in some trials when red light is used before or after exercise. A review summarized by Function Smart reports that ATP production in muscle cells can increase substantially and that delayed onset muscle soreness (DOMS) may be reduced by roughly 50 percent in some protocols. Other trials show faster recovery of strength and lower blood levels of creatine kinase, a marker of muscle damage, after hard workouts.
A detailed review of 46 clinical studies published in a sports science journal (described in the PubMed‑indexed article on photobiomodulation in human muscle tissue) found that using red or near‑infrared light as “pre‑conditioning” before strength exercise often increased the number of repetitions to fatigue and reduced biochemical markers of damage. However, results were not consistent across all studies, and outcomes depended heavily on dose, wavelength, and timing.
On the other side of the spectrum, an evidence review discussed by TrainingPeaks looked at the same landscape and reached a more skeptical conclusion. In their assessment, benefits for athletic performance are interesting but not convincingly demonstrated, and they did not recommend that athletes invest significant money in panels solely for performance gains.
Taken together, the muscle and performance data suggest that red light therapy can support recovery and reduce soreness for at least some people, especially when properly dosed, but it is not a guaranteed performance booster and should be treated as an adjunct rather than a primary training tool.
Sleep, Alertness, and Daytime Energy
Sleep is one of the most powerful levers for afternoon energy. If a therapy helps you get deeper, more stable sleep at night, the benefits often show up the next afternoon, not just the following morning.
Athletic Lab’s summary of the research highlights a placebo‑controlled study in Chinese female basketball players where evening red light sessions improved sleep quality and nighttime melatonin levels compared with placebo. The same article notes morning research where red light exposure during or shortly after waking reduced sleep inertia and improved alertness and short‑term performance, based on work by Figueiro and colleagues.
Clinical overviews from UCLA Health and University Hospitals also note that photobiomodulation is being explored for sleep, cognitive function, and chronic pain. A small dementia study cited by UCLA Health reported cognitive improvements with daily head‑mounted red light over eight weeks. These findings are early, but they support the idea that red light can influence brain‑related functions like sleep and attention.
At the same time, Stanford Medicine experts caution that the data for red light in areas such as sleep and athletic performance are still limited. The evidence for skin and hair is much stronger than for broader wellness claims. So while it is reasonable to hope for better sleep and more stable energy as part of a comprehensive routine, it is not accurate to say red light therapy has been definitively proven to fix afternoon fatigue.
Pain, Inflammation, and Perceived Energy
Energy is not only about mitochondria and hormones. Chronic pain and low‑grade inflammation drain motivation and make the afternoon feel like a mountain to climb. Several medical overviews, including those from Cleveland Clinic, WebMD, UCLA Health, and University Hospitals, describe red light therapy’s role in managing certain kinds of pain:
Reviews report that photobiomodulation can reduce pain and inflammation in some musculoskeletal conditions, tendon problems, and certain types of arthritis, at least over the short term. One review of chronic pain found meaningful reductions in pain scores after red light therapy, although benefits tended to fade after treatment stopped, implying that ongoing sessions are needed.
In practical terms, people who have less muscle and joint discomfort often move more, sit less stiffly at their desks, and feel less exhausted by the end of the day. So while pain relief is not the same as an energy drink, it can be an important indirect route to better afternoon energy.
What’s Not Proven Yet
A Stanford Medicine explainer on red light therapy makes an important point: there is real evidence that red light can change biology, but that is not the same as saying it is a panacea for many different health conditions. They consider the evidence for hair growth and wrinkle reduction fairly robust. For wound healing, sports performance, sleep, or whole‑body wellness, the data are promising but inconsistent and often based on small studies.
WebMD and Cleveland Clinic both emphasize that many commercially promoted uses, such as weight loss or dramatic mood enhancement, currently lack strong scientific support. TrainingPeaks echoes this caution for performance claims. ACE Fitness notes that while photobiomodulation can improve some recovery markers, guidelines for optimal frequency, intensity, and duration are not yet established.
For afternoon energy specifically, there are no large, direct trials showing that desk workers who do red light therapy in the afternoon perform better or feel less tired than those who do not. Any recommendations in that direction are informed extrapolations from sleep, recovery, and pain studies, not direct proof.
How These Effects Translate Into Afternoon Energy
Even without a direct “afternoon slump study,” the existing science offers a plausible path for how red light therapy could support mid‑day energy when integrated thoughtfully.
Mechanism One: Better Sleep Leads to Better Afternoons
Evening red light sessions have been shown to improve sleep quality and melatonin in athletes in at least one placebo‑controlled trial. If you sleep more deeply and wake more refreshed, you naturally bring more reserves into the next day. Instead of relying on coffee and sugar to prop up an already depleted system, your body is better rested, and your afternoon dip is less severe.
I often encourage people who struggle with both sleep and afternoon fatigue to think of red light therapy as a gentle nudge toward healthier circadian rhythms. Combined with a consistent bedtime, a dark bedroom, and a wind‑down routine, short evening sessions may help you fall asleep more easily and stay asleep longer. The payoff typically shows up right where you feel it most: that post‑lunch window.
Mechanism Two: Less Soreness, More Willingness to Move
DOMS and lingering muscle tension do not just make workouts uncomfortable; they make sitting and concentrating harder. Multiple sports‑medicine summaries report that red light therapy, used around exercise, can reduce soreness and accelerate recovery for some people. When muscles recover more fully between sessions, everyday movement feels easier.
In practical terms, someone who is less sore is more willing to take walking breaks, stretch mid‑afternoon, or do a few light movements between meetings. That kind of physical activity boosts blood flow, brings more oxygen to the brain, and often provides a natural lift in alertness. Red light therapy does not directly replace movement, but by reducing discomfort, it can make movement more accessible, which in turn supports energy.
Mechanism Three: Acute Alertness and Circulatory Support
Morning research suggests that red light exposure can reduce sleep inertia and improve alertness shortly after waking. Although those trials did not specifically focus on afternoon sessions, the underlying mechanism is similar: light‑induced changes in mitochondrial function and blood flow.
For some people, a short mid‑day session functions as a structured, screen‑free break with potential circulatory and cellular benefits. Unlike caffeine, which temporarily stimulates the nervous system, red light aims to improve the efficiency of the cells doing the work. The experience itself is usually calm and warm, more like a gentle reset than a jolt.
A Practical At‑Home Routine for Supporting Afternoon Energy
Because dosing research is still evolving, there is no single “official” protocol for boosting afternoon energy. However, several patterns show up repeatedly across clinical and sports‑medicine articles that we can reasonably adapt for at‑home use, while being transparent about the evidence strength.
Here is a simple way to think about timing, based on what current research and clinical practice suggest.
Time of day |
Primary goal |
Typical approach described in research and clinics |
Evidence strength for that goal |
Morning |
Reduce grogginess and improve readiness |
Short session with red or near‑infrared light soon after waking, usually around 10 to 20 minutes facing a panel at a comfortable distance |
Direct evidence for reduced sleep inertia and better alertness; indirect for long‑term energy |
Mid‑afternoon |
Gentle reset and circulation support |
Brief break session after lunch or during the slump, again roughly 10 to 20 minutes, focusing on large muscle groups or tension areas |
Extrapolated from circulation and recovery studies; not directly tested for office fatigue |
Evening |
Support recovery and sleep quality |
Session in the early evening, away from bright blue‑rich screens, often 10 to 20 minutes, targeting sore muscles or using a full‑body bed or panel |
Evidence for better sleep and melatonin in athletes; mixed but promising for pain |
Session durations in the 10 to 20 minute range per area are commonly mentioned in clinical settings and in articles from Function Smart, the Physical Achievement Center, red light therapy clinics, and wellness centers. Some protocols use slightly shorter or longer times, but there is no indication that very long exposures are better. In fact, Athletic Lab notes that benefits appear to plateau beyond about 20 minutes in their setup.
Choosing an At‑Home Device
From a wellness and energy perspective, most people start with either a wall‑mounted or free‑standing panel, a smaller desktop panel, or a full‑body bed session at a local clinic.
Medical sources such as UCLA Health, WebMD, and Cleveland Clinic highlight a few important points about devices:
At‑home devices are usually less powerful than those used in dermatology clinics or research labs. That can be a safety advantage, but it also means results may be more modest and slower.
Some devices are cleared by the Food and Drug Administration, which mainly speaks to safety and similarity to existing devices, not to guaranteed effectiveness. Terms like “FDA certified” are marketing language, not regulatory categories.
Panel devices that clearly list their wavelengths and irradiance (power per area) make it easier to approximate research‑like doses. Look for ranges around 630 to 670 nanometers for red and 800 to 850 nanometers for near‑infrared, since those bands show up repeatedly in the sports and dermatology literature.
If you have darker skin or any history of pigmentation changes, dermatology organizations recommend talking with a dermatologist before starting at‑home facial treatments, because darker skin can sometimes be more prone to hyperpigmentation from various light‑based therapies.
Where to Aim the Light
For general energy support, most people do not need to micromanage exact muscle groups. Panels are usually positioned to cover as much of the front or back of the body as is comfortable. When afternoon fatigue is tied to specific discomforts, such as neck and shoulder tension from computer work or sore legs from training, it can make sense to devote part of each session specifically to those areas.
Sports‑medicine sources commonly apply light over the major muscles used in training, such as quadriceps, hamstrings, and calves for runners or glutes and upper back for weightlifters. For someone whose “sport” is mostly sitting at a desk, the analog might be the mid‑back, neck, and hips.
Always follow the manufacturer’s guidance about distance and exposure time, and avoid shining light directly into your eyes. Clinics such as Restore and aesthetic practices offering red light beds typically provide protective goggles and advise clients to keep their eyes closed during sessions.
Safety, Precautions, and When to Talk to Your Doctor
Across medical summaries from Stanford Medicine, Cleveland Clinic, WebMD, UCLA Health, and University Hospitals, a few safety themes emerge.
Red light therapy, when used correctly, is generally considered low risk and non‑invasive. It does not emit ultraviolet radiation and does not appear to cause cancer.
Short‑term side effects are usually mild when they occur, such as transient redness or warmth. However, overexposure or use of high‑intensity devices too close to the skin can cause irritation.
Eye safety matters. Because high‑intensity light can damage the eyes, especially with laser devices, you should avoid staring into the light and use proper eye protection when treating the face or when devices feel uncomfortably bright.
People who are pregnant, on photosensitizing medications, have a history of skin cancer, or have conditions like lupus or epilepsy should consult a healthcare professional before starting red light therapy.
If your afternoon fatigue is severe, new, or accompanied by symptoms such as shortness of breath, chest pain, dizziness, or unexplained weight loss, you should talk to a physician rather than relying on any wellness modality, including red light therapy.
Pros and Cons for People Seeking Better Afternoon Energy
When you look specifically through the lens of afternoon energy, red light therapy has both appealing strengths and real limitations.
Potential Advantages
From an energy‑support standpoint, red light therapy is non‑invasive, usually painless, and generally safe when used as directed. It can be built into existing habits: a morning session before checking your cell phone, a short mid‑afternoon break away from screens, or an evening session paired with stretching.
Evidence from athletic and medical settings suggests it can reduce soreness, improve some aspects of recovery, and support better sleep in certain populations. Those outcomes can all play into more stable afternoon energy, especially for people who train hard, work long hours, or live with chronic musculoskeletal discomfort.
Unlike stimulants, red light does not “push” your nervous system. Instead, it appears to help your cells work more efficiently. That makes it a good fit for people who cannot tolerate more caffeine or who already feel wired and tired.
Limitations and Drawbacks
On the other hand, red light therapy is not a quick fix for deep‑seated fatigue. If you are burning the candle at both ends, skipping meals, or dealing with untreated medical conditions, a light panel cannot solve the root problem.
The evidence base for athletic performance and generalized wellness is mixed. Several reviews find promising improvements in recovery markers, but there is no definitive consensus that red light therapy will dramatically transform performance or day‑to‑day energy for everyone. TrainingPeaks explicitly calls it “interesting yet unproven” for performance, and Stanford Medicine stresses the need for more robust clinical data.
Quality devices can be expensive. Home panels and beds range from under a hundred dollars to several thousand, and clinic sessions are often not covered by insurance. Since benefits tend to fade when treatment stops, ongoing use may be needed, which adds cost and time.
Finally, there is a risk of distraction. It is easy to focus on gadgets and overlook fundamentals. In my work, I rarely recommend red light therapy without simultaneously addressing sleep routines, movement, stress management, and nutrition. The light can be a powerful adjunct, but it cannot substitute for those pillars.
Common Questions About Red Light Therapy and Afternoon Energy
Will a single red light session fix my afternoon slump?
A single session may leave you feeling relaxed and a bit lighter, especially if it prompts you to step away from your screen and breathe for 15 minutes. However, most research and clinical reports describe benefits building over weeks of consistent use, not from isolated sessions. If you are hoping for sustainable changes in afternoon energy, it is more realistic to think in terms of a daily or near‑daily routine integrated with healthy sleep and recovery practices.
Is it safe to use red light therapy every day?
Medical sources generally describe daily use as safe at appropriate doses, particularly with LED‑based devices. Clinical protocols in athletic and dermatology settings often involve multiple sessions per week or even daily treatments for limited periods. That said, more is not always better. Overexposure can irritate the skin, and there is no evidence that very long sessions provide added benefits. Following device instructions, starting with moderate durations, and checking in with a healthcare professional if you have underlying conditions is the best approach.
How long does it usually take to notice a difference?
Timelines vary. In some athletic studies, participants reported reduced soreness or improved performance within a few weeks. Sleep studies with evening red light used durations around eight to twelve weeks. For many of the people I advise, the most common pattern is subtle early changes in sleep or soreness within two to four weeks, followed by more noticeable shifts in daytime resilience over the next month as the routine stabilizes. If you see no change at all after several weeks of consistent, properly dosed use, it may not be a good fit for you, or other factors may be overshadowing any benefits.
Red light therapy sits at an interesting intersection of hard science and practical wellness. We know it can influence cellular energy production, circulation, and inflammation. We have early but encouraging data for sleep, recovery, and pain. We also have clear reminders from Stanford Medicine, Cleveland Clinic, and other expert centers that this is not a cure‑all, and that evidence for broad performance and energy claims is still emerging.
If you struggle with afternoon crashes and are already working on the basics—regular sleep, nourishing food, smart movement, and stress management—thoughtfully used red light therapy can be a gentle, science‑informed tool to support your body’s recovery and resilience. Used with realistic expectations and good guidance, it is less about chasing a quick buzz and more about building the kind of deep, cellular capacity that lets you show up with steadier energy, day after day.
References
- https://lms-dev.api.berkeley.edu/red-light-tjerapy
- https://pmc.ncbi.nlm.nih.gov/articles/PMC5167494/
- https://med.stanford.edu/news/insights/2025/02/red-light-therapy-skin-hair-medical-clinics.html
- https://my.clevelandclinic.org/health/articles/22114-red-light-therapy
- https://www.gundersenhealth.org/health-wellness/aging-well/exploring-the-benefits-of-red-light-therapy
- https://www.uclahealth.org/news/article/5-health-benefits-red-light-therapy
- https://www.acefitness.org/resources/pros/expert-articles/8857/red-light-therapy-and-post-exercise-recovery-the-physiology-research-and-practical-considerations/?srsltid=AfmBOopjVkwR_HSqaIjDsi9UmnLtnLPhQbXd55B2ArQk41Ls_mT6nZxE
- https://www.uhhospitals.org/blog/articles/2025/06/what-you-should-know-about-red-light-therapy
- https://www.physio-pedia.com/Red_Light_Therapy_and_Muscle_Recovery
- https://www.athleticlab.com/red-light-therapy-for-athletes/
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