Hyperbaric Oxygen Therapy for High-Performance Athlete Recovery

Key Points

• HBOT is increasingly explored as a supportive treatment in sports rehabilitation.
• Its strongest rationale is in injuries involving tissue hypoxia, swelling, impaired circulation, delayed healing, collagen remodelling, graft integration, and bone vascular compromise.
• The evidence is most encouraging in selected ligament injuries, particularly grade 2 MCL injury and early ACL reconstruction graft maturation, as well as bone marrow oedema, avascular necrosis, and some muscle injuries.
• HBOT should currently be viewed as an adjunctive therapy alongside standard sports medicine care, physiotherapy rehabilitation, orthopedic management, and surgery when indicated.

Introduction

Sports and exercise-related injuries affect individuals across all levels of physical activity, from elite athletes to recreational exercisers. Muscle strains, ligament sprains, tendon injuries, stress fractures, bone marrow oedema, and post-surgical recovery challenges can significantly affect physical function, activity levels, and recovery.

Hyperbaric oxygen therapy (HBOT) is attracting growing interest in sports and musculoskeletal rehabilitation because of its potential to enhance oxygen delivery and support processes involved in oedema reduction, inflammation modulation, angiogenesis, collagen synthesis, extracellular matrix remodelling, and tissue repair ^{1 2 3}. Current evidence suggests HBOT may have a role in selected conditions associated with impaired oxygenation or delayed healing, including certain muscle, tendon, and ligament injuries, bone marrow oedema, avascular necrosis, and some post-surgical recovery settings ^{1 4 5}.

The evidence is encouraging but still evolving. HBOT is not a replacement for standard medical care, rehabilitation, physiotherapy, orthopedic management, or surgery when indicated. It should currently be considered an adjunctive therapy that may support recovery in selected clinical settings.

Where HBOT Fits in Sports Injury Care

Sports injury healing progresses through inflammatory, proliferative, and remodelling phases. Oxygen plays an important role throughout tissue healing and regeneration, including inflammatory regulation, fibroblast activity, collagen production, angiogenesis, and tissue remodelling ².

HBOT may therefore be most relevant in injuries involving significant oedema, tissue hypoxia, vascular compromise, delayed healing, bone vascular injury, pre-collapse avascular necrosis, or post-surgical tissue integration ^{1 4 6}.

Hyperbaric oxygen therapy involves breathing near-pure medical oxygen under increased atmospheric pressure inside a hyperbaric chamber, generally at pressures of 2.0 ATA or greater ^{1 2}. Typical HBOT sessions usually last between 90 and 120 minutes and are commonly delivered on consecutive days, with treatment courses ranging from approximately 5 to 30 sessions depending on injury severity, clinical response, and treatment goals. However, protocols vary according to the injury type and individual medical assessment.

Mechanisms of Action

HBOT substantially increases dissolved oxygen levels in plasma, improving oxygen availability even in tissues where circulation or diffusion may be compromised. Beyond oxygen delivery alone, proposed mechanisms relevant to sports injury recovery include:

• Oedema reduction
• Improved microcirculation
• Inflammation modulation
• Angiogenesis and neovascularisation
• Stem cell mobilisation
• Collagen synthesis and extracellular matrix remodelling
• Muscle regeneration
• Support for bone healing and tissue repair ^{1 2 3 4}

These mechanisms provide a strong biological rationale for HBOT in selected injuries, particularly where swelling, hypoxia, impaired vascularity, or delayed repair are limiting recovery.

What the Evidence Shows

Research into HBOT for sports and musculoskeletal injuries is promising but heterogeneous ^{1 2 3}. Published studies have reported improvements in muscle recovery, tendon-bone integration, collagen synthesis, ligament healing markers, bone marrow oedema, and selected post-operative recovery outcomes.

Overall, HBOT appears most appropriate as an adjunct within a multidisciplinary rehabilitation plan, rather than as a standalone treatment ^{1 2}.

Ligament and Tendon Injuries

Ligament and tendon injuries are major musculoskeletal health concerns affecting more than 1.71 billion people worldwide and are associated with significant functional limitations and reduced quality of life. Babel et al.'s 2025 systematic review on HBOT for ligament and tendon injuries evaluated 13 studies involving 693 participants/subjects, including both animal and human studies ⁵.

HBOT Protocols

• Pressure range: 1.3–2.8 ATA
• Session duration: 60–120 minutes
• Treatment duration commonly ranged from 5–10 consecutive days, although some studies used longer protocols

Outcomes Assessed

The review assessed histological, biomechanical, biochemical, radiological, and functional outcomes, including collagen synthesis, fibre organisation, tendon-bone integration, graft healing, tensile strength, pain, and functional recovery ⁵.

Key Findings

HBOT was associated with:

• Improved collagen synthesis
• Better fibre alignment
• Increased extracellular matrix deposition
• Improved tensile strength
• Enhanced tendon-bone integration
• Improved graft healing markers
• Pain reduction
• Improved functional recovery

HBOT may also have a role in post-operative ligament recovery, particularly after ACL reconstruction, by supporting graft healing, ligamentisation, and tendon-bone integration. However, evidence that HBOT directly reduces graft failure or re-injury rates in human athletes remains limited, and larger controlled studies are still needed ⁵.

Protocols were heterogeneous across studies; human clinical evidence remains limited, and larger standardised clinical trials are still needed to better define optimal treatment protocols and long-term outcomes ⁵.

Although clinical research in humans is still developing, early findings are encouraging and are supported by a growing body of preclinical evidence. Animal studies are particularly valuable in this field because they allow direct assessment of ligament healing, collagen organisation, tendon-bone integration, and biomechanical strength, which are difficult to evaluate directly in human athletes. Larger randomised controlled trials will help further clarify the role of HBOT in sports and musculoskeletal rehabilitation.

MCL Injuries

For native ligament injuries such as MCL sprains, the human evidence remains relatively small but clinically relevant. One of the most directly relevant clinical studies was a 2019 investigation into professional or semi-professional rugby players with grade 2 MCL injuries, where the HBOT group returned to play sooner than controls, approximately 31.4 versus 42.1 days ⁷. This is particularly relevant in sport, where return-to-play time is a meaningful functional outcome. The relatively limited number of randomised or sham-controlled studies in this area most likely reflects the practical challenges of conducting blinded HBOT research in elite athletic settings, where treatment exposure, rehabilitation programmes, competition schedules, and athlete availability can be difficult to standardise. Despite these challenges, the available findings provide encouraging early clinical support for HBOT as a potential adjunct in selected ligament injuries.

Animal MCL studies provide additional biological support, showing improvements in collagen synthesis, extracellular matrix deposition, tensile strength, stiffness, and ligament remodelling pathways after HBOT exposure ^{8 9 10}.

ACL Reconstruction and Graft Healing

ACL reconstruction and graft healing are among the more promising newer areas of HBOT research. Animal ACL reconstruction studies have demonstrated improved graft integration, reduced tunnel widening, denser Sharpey-like fibres, and improved biomechanical properties after postoperative HBOT ^{11 12}.

In a 2026 pilot matched-cohort study involving 52 patients undergoing ACL reconstruction (26 HBOT, 26 controls), the HBOT group demonstrated significantly lower graft signal intensity and reduced bone marrow oedema at the graft-bone tunnel interface on MRI at 4 months, suggesting improved early graft maturation and integration ⁶. These findings support a potential role for adjuvant HBOT in accelerating early graft healing and optimising post-operative recovery following ACL reconstruction, although larger controlled studies are still needed ⁶.

ACL Rupture Without Reconstruction

There is currently no good clinical evidence that HBOT alone heals a torn ACL or restores ACL continuity after complete rupture. The mechanistic ACL literature is mainly focused on collagen signalling, extracellular matrix remodelling, graft integration, and postoperative healing, rather than spontaneous restoration of ACL continuity ^{13 6}.

Muscle Injuries

Muscle injury and recovery represent another promising area of HBOT research because oxygen availability is closely linked to inflammation control, macrophage activity, satellite-cell activation, myofibre regeneration, mitochondrial function, and recovery after exercise-induced muscle damage ^{14 15}. Experimental studies have consistently demonstrated encouraging effects on muscle recovery and regeneration.

In athlete recovery settings, HBOT has also been explored for fatigue and performance restoration. Ishii et al. described HBOT use during the Nagano Winter Olympics as an adjunct for muscular fatigue, while later studies reported improved blood lactate clearance, maximal oxygen consumption, and oxygen consumption at the anaerobic threshold following HBOT exposure ^{16 17 18}. This is relevant because exercise-induced muscle damage and delayed-onset muscle soreness can temporarily reduce force production, training quality, and performance, and may increase injury risk if athletes return too early ^{19 20}.

Human muscle-injury studies provide several clinically interesting signals, although outcomes vary according to injury model, sample size, timing of treatment, pressure protocol, and severity of muscle injury. Webster et al. found that HBOT helped preserve isometric peak torque and reduce pain and soreness by day 5 after exercise-induced muscle damage, while Staples et al. reported significantly improved quadriceps torque recovery after DOMS induction ^{21 22}. Other small, controlled studies did not show clear benefit, highlighting the importance of protocol selection, injury severity, and appropriate patient selection when interpreting the evidence ^{23 24 25}.

The most directly relevant athlete study is Chen et al., who evaluated 41 baseball players with exercise-related muscle soreness or grade I muscle strain while they continued training. HBOT was associated with significant reductions in glutamic oxaloacetic transaminase, myoglobin, creatine phosphokinase, and pain after treatment, with improvements in pain intensity and interference compared with placebo ²⁶.

Overall, the muscle-injury evidence is encouraging, particularly where oedema, biochemical muscle injury, fatigue, or delayed recovery are present, but HBOT should still be considered an adjunct to structured rehabilitation rather than a replacement for standard care.

Bone Marrow Oedema and Exercise-Related Avascular Necrosis

Avascular necrosis (AVN), also known as osteonecrosis, is a relatively uncommon but potentially debilitating orthopedic condition that can occur in physically active individuals. Bone marrow oedema and avascular necrosis are biologically plausible applications for HBOT because impaired oxygen delivery, vascular compromise, and bone repair mechanisms are central to the underlying disease process ^{1 2 4}.

The most encouraging results have been reported in early or pre-collapse AVN. Reis et al. (2003) reported normalisation of MRI findings in 81% of HBOT-treated patients compared with 17% in untreated controls, while Camporesi et al. (2010) demonstrated improvements in pain, mobility, and hip function following 30 HBOT sessions ^{27 28}.

Overall, current evidence suggests HBOT may offer clinically meaningful benefits in early-stage AVN before structural collapse occurs, although larger standardised clinical trials are still needed ^{27 28}.

Safety and Clinical Oversight

HBOT is generally considered safe when delivered in an appropriate clinical setting under trained medical supervision ^{1 2 29}. Most adverse effects are mild and manageable. The most common complication is middle ear barotrauma, while serious complications such as oxygen toxicity are uncommon ²⁹.

Appropriate screening, patient selection, chamber safety procedures, and clinical monitoring remain essential. This is especially important for athletes returning to training or competition, where treatment should be integrated with rehabilitation planning rather than used in isolation.

Overall Conclusion

HBOT has a strong biological rationale and reasonable mechanistic support for selected sports and musculoskeletal injuries, especially where tissue hypoxia, oedema, impaired circulation, delayed healing, collagen remodelling, graft integration, or bone vascular compromise are clinically relevant.

The ligament evidence is particularly encouraging in two areas: grade 2 MCL injury and early ACL reconstruction graft maturation. Animal studies provide meaningful structural and biomechanical insight, while early human studies suggest potential clinical value.

At present, HBOT should be viewed as a promising adjunctive therapy within sports medicine and orthopedic rehabilitation. Larger, well-designed human studies are still needed to define optimal protocols, patient selection, return-to-play outcomes, reinjury rates, and long-term functional benefits.

References