Hyperbaric oxygen therapy (HBO), as a new technological medical approach, has gradually been widely adopted in the field of health care. Among its many benefits, assisting post-exercise recovery is an important application of hyperbaric oxygen therapy.

Hyperbaric oxygen therapy is a treatment method in which patients breathe pure oxygen at pressures exceeding one atmosphere on a cyclical basis. The principle behind this therapy involves placing athletes in an environment with atmospheric pressure higher than normal—typically maintained between 2.0 and 2.5 kPa. An air compressor then pressurizes the air, introducing fresh, clean air into the chamber. An oxygen concentrator ensures that the oxygen concentration within the chamber remains within a specific range, thereby delivering oxygen to the chamber. This process increases the body's oxygen storage capacity, enhances the amount of physically dissolved oxygen in the blood, and improves the body's ability to take up and utilize oxygen. As a result, blood oxygen levels and blood oxygen saturation rise, boosting the oxygen’s ability to diffuse into tissues and supplying tissues with ample oxygen, thus restoring cellular vitality. Moreover, the physical effects of the high-pressure environment and high-oxygen concentration help alleviate systemic hypoxia.

The issue of recovery from fatigue after training or competition is receiving increasing attention. Hyperbaric oxygen therapy has already been adopted by various countries to help athletes recover from overexertion and sports-related injuries. Before daily training sessions and major competitions, leveraging the secret weapon of hyperbaric chambers can quickly recharge athletes, shorten the time needed for their bodily functions to return to normal levels, enable them to handle higher training intensities, and deliver even better performances.

Oxygen plays a critically important role in both substance metabolism and energy metabolism. After prolonged, intense exercise, the body’s oxygen demand increases along with its oxygen consumption. At this point, the body is forced to switch to anaerobic respiration, leading to a buildup of acidic metabolic byproducts—such as lactic acid—that easily induce fatigue in muscles and blood. As a result, various blood indicators—including hemoglobin levels, blood oxygen saturation, and serum parameters—undergo changes within the body, thereby causing a decline in physiological functions and a reduction in athletic performance, ultimately triggering exercise-induced fatigue.

Recovery after exercise is a complex process, and the rate at which lactate is cleared represents an important indicator of recovery. Understanding its dynamic changes can greatly assist athletes in optimizing their physical recovery. Following intense exercise, due to tissue hypoxia, pyruvate is reduced to lactate under the catalysis of lactate dehydrogenase. Lactate is an acidic metabolic byproduct; when its concentration rises, it can cause a decrease in tissue pH. This, in turn, leads to an imbalance in the body’s electrolytes, impairing muscle contractile function, inhibiting the binding of oxygen to hemoglobin, reducing the body’s energy supply, diminishing work capacity, and ultimately triggering muscle fatigue.

Through hyperbaric oxygen therapy, athletes who inhale high-pressure oxygen after exercise not only increase the oxygen content in their blood and alleviate oxygen deficit following intense exercise, but also accelerate the rate at which lactic acid is cleared from the body, thereby enhancing the body’s recovery speed after strenuous physical activity.

The oxygen consumed by the human body is primarily carried by hemoglobin. Clinically, blood oxygen saturation is commonly used to reflect changes in the oxygen content of the blood—specifically, the percentage change in the amount of oxygen bound relative to the total oxygen-binding capacity of the entire blood volume. Blood oxygen saturation is an important indicator reflecting the body's oxygen supply and utilization. Therefore, inhaling hyperbaric oxygen can alleviate relative hypoxia, enhance the reversible binding of hemoglobin to oxygen, promote the body's recovery of blood oxygen saturation, and improve the blood's oxygen-carrying capacity, thereby accelerating physical recovery and quickly relieving fatigue after intense physical activity.

Blood urea nitrogen is the primary end-product of human protein metabolism. When the body ingests large amounts of protein, its metabolism produces significant quantities of urea nitrogen. During intense, high-intensity exercise, urine output decreases while the body's oxygen consumption rises sharply. In the metabolic process of glucose breakdown, pyruvate is reduced to lactate, leading to a buildup of lactic acid in the body. This reduces the efficiency of glycolysis as an energy source and, consequently, increases protein catabolism, causing blood urea nitrogen levels to rise and triggering fatigue.

Moreover, HBO preconditioning increases the partial pressure of oxygen in the blood, promoting the reconversion of lactate into glycogen within hepatocytes and enhancing lactate excretion by the kidneys and skin. As a result, the production of lactate and blood urea nitrogen is rapidly reduced, thereby facilitating the clearance of lactate, blood urea nitrogen, and other acidic metabolites. Additionally, urine output significantly increases following HBO preconditioning, which reduces the reabsorption of blood urea nitrogen during its renal excretion process, thus alleviating fatigue.

Studies have found that both high-intensity muscle exertion and extensive training volumes can increase serum CK (creatine kinase) activity. In particular, prolonged, intense exercise significantly elevates serum CK activity. Under these conditions, the permeability of muscle cells changes, causing CK from the muscle cells to be released into the bloodstream, thereby increasing the burden on the blood to transport oxygen.

Hyperbaric oxygen therapy can stimulate the body to produce more antioxidant enzymes under conditions of ischemia and hypoxia, thereby accelerating the clearance of free radicals. This effectively prevents free radical-induced damage to tissue cells and helps relieve fatigue. In addition, hyperbaric oxygen therapy is highly effective in treating post-exercise injuries. It increases the availability of dissolved oxygen plasma, enhances oxygen delivery, and improves tissue viability in ischemic areas, promoting the recovery of damaged cells and alleviating exercise-induced fatigue.

The liver is capable of storing glycogen and providing energy, making it a major energy-providing organ that plays an important role in physical exercise. If prolonged, continuous exercise leads to depletion of the body’s glycogen stores without adequate recovery, resulting in fatigue, this can explain why excessive exercise often causes pain in the liver region. Hyperbaric oxygen therapy is highly effective in treating damage to the liver’s tissue structure, ensuring sufficient oxygen supply within hepatocytes, promoting extensive proliferation of mitochondria, and increasing ATP (adenosine triphosphate) production. Moreover, under hyperbaric oxygen conditions, the hepatic sinusoids in liver tissue enlarge, blood circulation accelerates, and metabolic waste products are rapidly removed while nutrients are efficiently delivered. Therefore, hyperbaric oxygen therapy can restore the liver’s structure to a normal state, significantly improve hepatocyte function, and effectively relieve fatigue.

The heart is a strictly aerobic metabolic tissue with a high oxygen consumption, yet its blood supply remains relatively low. Consequently, the heart is an organ particularly vulnerable to hypoxic damage. Once myocardial workload increases, so does the heart’s oxygen demand. Hyperbaric oxygen therapy exerts its effects on myocardial cells following hypoxia primarily by slowing heart rate, reducing myocardial conduction velocity, weakening myocardial contractility, and decreasing myocardial oxygen consumption. It can rapidly replenish the substantial depletion of substances caused by exercise, increase the body’s glycogen reserves, improve the body’s hypoxic state, and play a certain role in promoting recovery from post-exercise fatigue.