The short answer: The mechanism is real but the clinical proof is early. Hyperbaric oxygen therapy (HBOT) drives mitochondrial biogenesis through the hyperoxic-hypoxic paradox, and a 2023 meta-analysis found a large pooled effect on fibromyalgia symptoms (SMD −1.56). But the most rigorous sham-controlled trial in long COVID (HOT-LoCO, 2025, n=80) found no advantage over placebo on physical function. Treat “more energy” as a plausible, investigational benefit, not an established one.
Disclosure: Superhuman Chambers manufactures and sells hyperbaric chambers for wellness operators. This article summarizes published research and is not medical advice. HBOT is not FDA-cleared for energy, fatigue, chronic fatigue syndrome, fibromyalgia, or long COVID; those uses are off-label. You are responsible for the protocols, claims, screening, and regulatory compliance in your jurisdiction.
Why “energy” is the hardest claim to make well
Energy is the benefit clients ask about most and the one that is hardest to pin down. When someone says they want more energy, they can mean very different things: less physical fatigue after exertion, fewer afternoon crashes, better mental stamina, faster recovery between hard days, or simply not feeling wiped out by ordinary life. Those are related experiences, but they are driven by different physiology and measured by different instruments.
That matters because HBOT research does not test “energy” as a single outcome. It tests fatigue in specific populations — people with fibromyalgia, post-COVID syndrome, chronic fatigue, or the general decline that comes with aging — using validated fatigue and quality-of-life scales. A result in one of those populations does not automatically transfer to a healthy person who just wants a lift. The honest way to write and talk about HBOT and energy is to keep the population, the protocol, and the specific outcome attached to every claim.
Fatigue is also one of the most placebo-responsive symptoms in medicine. People who commit to a multi-week protocol, change their routine, and expect to feel better often do — regardless of the active ingredient. That is exactly why the sham-controlled trials below matter more than the glowing single-arm reports.
How HBOT could raise cellular energy
The energy story starts in the mitochondria, and the mechanism is genuinely interesting rather than marketing hand-waving. HBOT works less by flooding the body with oxygen and more by using intermittent oxygen swings as a signal.
The core idea is the hyperoxic-hypoxic paradox: breathing 100% oxygen under pressure and then returning to normal air creates a sharp drop in oxygen tension that the body reads as if it were oxygen-starved, even though no real hypoxia occurred. That signal switches on regenerative and metabolic pathways — HIF-1α, SIRT1, and NAD⁺ signaling — without the damage of actual hypoxia. Over a full course, this appears to shift cells toward building new, better-functioning mitochondria.
| Mechanism | What happens | Why it could affect energy |
|---|---|---|
| Hyperoxic-hypoxic paradox | Intermittent 100% O₂ then return to air is read as a hypoxic signal | Activates HIF-1α and SIRT1 regenerative pathways without true hypoxia |
| NAD⁺ / SIRT1 signaling | Hyperoxia shifts the NAD⁺/NADH balance, activating SIRT1 | SIRT1 drives mitochondrial biogenesis — the machinery that makes ATP |
| Time-dependent ROS response | Short courses raise reactive oxygen species; longer courses upregulate antioxidant defenses | Early sessions may transiently suppress, later sessions improve, mitochondrial activity (hormesis) |
| Increased dissolved oxygen | Pressure dissolves far more O₂ into plasma than breathing alone | More oxygen diffuses into tissue and mitochondria, the substrate for ATP production |
Two nuances are worth keeping in the room. First, the effect is time-dependent: laboratory work shows that a handful of early sessions can raise oxidative stress and briefly suppress mitochondrial activity, while a longer course (roughly 20–60 sessions) improves mitochondrial function as antioxidant defenses adapt. That is one reason single-session “energy boost” claims are weak — the mitochondrial benefit, if it exists, is a training effect, not a same-day one. Second, these are mostly mechanistic and animal or cell studies. A pathway that looks convincing in a dish is a hypothesis about human energy, not proof of it. Anyone who plans to shop hyperbaric chambers for an energy benefit should treat it as a multi-week commitment, not a same-day boost.
What the research shows, by population
The clinical evidence for HBOT and fatigue is a mix of striking positive trials and a sobering negative one. Reading it well means holding both at once.
| Study | Population | Protocol | Main finding |
|---|---|---|---|
| Efrati et al. 2015 (crossover, n=48) | Fibromyalgia (women) | 2.0 ATA, 100% O₂, 40 sessions, 90 min, 5×/wk | Tender points 17.3 → 8.9; physical-function and quality-of-life scores improved (p<0.001); brain-imaging changes |
| Chen et al. 2023 (review of 9 studies/288 patients; pain meta-analysis on 3 RCTs, n=113) | Fibromyalgia | Mixed protocols, 3–12 weeks | Pooled pain effect SMD −1.56 (95% CI −2.18 to −0.93); quality of life improved; flagged high risk of bias |
| Zilberman-Itskovich et al. 2022 (RCT, sham-controlled, n=73) | Post-COVID condition | 40 daily sessions | Energy domain improved vs sham (effect size d=0.52, p=0.029); cognition, sleep, and pain also improved |
| Kjellberg et al. 2025 — HOT-LoCO (RCT, sham-controlled, n=80) | Long COVID | 10 sessions, 2.4 bar, 100% O₂, vs sham air | No difference in physical function between HBOT and sham; both groups improved |
| Akarsu et al. 2013 (case series, n=16) | Chronic fatigue syndrome | 15 sessions over 3 weeks | Fatigue-severity and fatigue-quality-of-life scores improved (p<0.005); no control group |
| Hachmo et al. 2020 (single-arm, n=35) | Healthy adults ≥64 | 60 daily sessions | Telomere length +>20%; senescent cells reduced — a biological-aging marker, not an energy endpoint |
Fibromyalgia: the strongest positive signal
Fibromyalgia is where the fatigue evidence looks best. Efrati’s 2015 crossover trial reported large drops in tender-point counts and meaningful gains in physical function and quality of life, alongside changes on brain imaging. A 2023 systematic review covering nine studies then pooled the three randomized trials among them (113 patients) into a meta-analysis showing a large effect on pain (SMD −1.56). That is a headline-grade number, but it rests on a smaller slice of the review than the “288 patients” headline suggests.
The same meta-analysis, though, rated the evidence with caution: few randomized trials, heterogeneous protocols, and unclear or high risk of performance bias because most trials could not blind participants (you notice pressure). Large effect sizes from small, unblinded trials tend to shrink when tested more rigorously — which is exactly what the long-COVID data show next.
Long COVID: the trial that should change the conversation
Post-COVID fatigue produced one of the most encouraging HBOT results and one of the most important cautionary ones. Zilberman-Itskovich’s 2022 sham-controlled RCT found HBOT improved the energy domain and cognition versus a convincing sham. But the 2025 HOT-LoCO trial — also randomized, also sham-controlled, double-blind — found no advantage over placebo on physical function. Both groups got better, which is the fingerprint of placebo response and natural recovery doing the work.
Two well-designed sham-controlled trials disagreeing is not a reason to pick the one you like. It is the signal itself: the true effect on fatigue is either smaller than early trials suggested, or highly dependent on protocol (HOT-LoCO used only 10 sessions versus 40 in the positive trials). Either way, it argues for restraint.
Chronic fatigue syndrome and aging: thin and indirect
The chronic-fatigue-syndrome data are the weakest of the set — a 16-person case series with no control group and no blinding, whose own authors called for controlled trials. The aging data (Hachmo 2020) are often cited for “energy,” but they measured telomere length and senescent-cell counts, not day-to-day energy. They are fascinating biology and real cellular changes, but they do not demonstrate that a 70-year-old feels more energetic.
Fatigue is not one outcome — and placebo is powerful
Two threads run through all of the above and deserve to be stated plainly. First, “fatigue” fractures into physical fatigue, mental fatigue, sleep-driven tiredness, and post-exertional collapse, and HBOT’s evidence is uneven across them — better for the fibromyalgia symptom cluster, unproven for generic tiredness in healthy people. Sleep in particular is often the real driver of “more energy,” and it is a downstream marker rather than a direct HBOT target.
Second, fatigue responds strongly to expectation, routine change, and attention — the exact ingredients of a multi-week clinic protocol. That is not a knock on HBOT; it is why the sham-controlled evidence is the part that counts, and why single-arm testimonials, however sincere, cannot carry an energy claim.
Limitations and open questions
- The best-designed long-COVID trial was negative. HOT-LoCO (n=80) found no benefit over sham on physical function, tempering the positive RCT that preceded it.
- Most positive data come from one research group. The strongest fibromyalgia, long-COVID, and aging results come largely from a single Israeli group (Efrati/Hadanny), raising a replication and independence concern.
- Trials are small and often unblinded. The fibromyalgia meta-analysis explicitly flagged high risk of bias and likely inflated effects.
- Mechanistic ≠ clinical. Mitochondrial and telomere findings are surrogate biomarkers in small studies, not proof of improved everyday energy.
- Protocol matters and is unsettled. Positive trials used 40+ sessions at 2.0 ATA; the negative one used 10. Session count and pressure may explain the disagreement — but that is a hypothesis, not a settled protocol.
- No FDA clearance. Energy, fatigue, CFS, fibromyalgia, and long COVID are off-label; insurance generally does not cover them.
What this means for wellness operators
For operators, energy is a magnet topic and a liability if handled carelessly. The defensible position is to describe the mechanism honestly, present fatigue as an area of active and mixed research, and avoid promising a same-day lift or a cure for tiredness. Position HBOT as one possible support within a broader recovery and longevity approach, screen clients appropriately, and let realistic expectations — a multi-week course, individual variation, no guarantees — do the marketing. Clients who feel better and were told the truth become durable advocates; clients sold a miracle churn and complain.
If a client’s fatigue is significant or new, the right move is a referral to a physician, not a chamber. Fatigue can be a symptom of conditions HBOT does nothing for, and screening for that is part of running a credible operation. For a grounding in how the therapy works and where it is proven, our overview of hyperbaric oxygen therapy and the pressure levels explained guide are good next reads. Operators weighing a chamber for a recovery-focused studio can talk to our team about protocols and positioning.
References
- Hadanny A, Efrati S (2020). The Hyperoxic-Hypoxic Paradox. Biomolecules 10(6):958. https://pmc.ncbi.nlm.nih.gov/articles/PMC7355982/
- Schottlender N, Gottfried I, Ashery U (2021). Hyperbaric Oxygen Treatment: Effects on Mitochondrial Function and Oxidative Stress. Biomolecules 11(12):1827. https://pmc.ncbi.nlm.nih.gov/articles/PMC8699286/
- Efrati S, et al. (2015). Hyperbaric Oxygen Therapy Can Diminish Fibromyalgia Syndrome — Prospective Clinical Trial. PLoS One 10(5):e0127012. https://pmc.ncbi.nlm.nih.gov/articles/PMC4444341/
- Chen X, et al. (2023). Efficacy and safety of hyperbaric oxygen therapy for fibromyalgia: a systematic review and meta-analysis. BMJ Open. https://pmc.ncbi.nlm.nih.gov/articles/PMC9872467/
- Zilberman-Itskovich S, et al. (2022). Hyperbaric oxygen therapy improves neurocognitive functions and symptoms of post-COVID condition: randomized controlled trial. Scientific Reports 12:11252. https://pubmed.ncbi.nlm.nih.gov/35821512/
- Kjellberg A, et al. (2025). Ten sessions of hyperbaric oxygen versus sham in long COVID (HOT-LoCO): a randomised, placebo-controlled, double-blind phase II trial. BMJ Open 15(4):e094386. https://pubmed.ncbi.nlm.nih.gov/40228859/
- Akarsu S, et al. (2013). The efficacy of hyperbaric oxygen therapy in the management of chronic fatigue syndrome. Undersea Hyperb Med 40(2):197–200. https://pubmed.ncbi.nlm.nih.gov/23682549/
- Hachmo Y, et al. (2020). Hyperbaric oxygen therapy increases telomere length and decreases immunosenescence in isolated blood cells. Aging (Albany NY) 12(22):22445–22456. https://pubmed.ncbi.nlm.nih.gov/33206062/
- U.S. FDA (2025). Follow Instructions for Safe Use of Hyperbaric Oxygen Therapy Devices — Letter to Health Care Providers. https://www.fda.gov/medical-devices/letters-health-care-providers/follow-instructions-safe-use-hyperbaric-oxygen-therapy-devices-letter-health-care-providers
- Undersea and Hyperbaric Medical Society. Hyperbaric Oxygen Therapy Indications. https://uhms.org/resources/featured-resources/hbo-indications.html