Molecular Hydrogen And Its Importance As Medicine In Sports

Sports is an activity comprising physical efforts and skills as the focus with the element of social involvement and competition. Concerning the health effects, sports is considered a double-edged sword. Positive health effects are attained through physical activity which is the key part of most sports. It also exerts some secondary effects that cause health benefits, for instance, personal development, psychosocial development, and less alcohol consumption. Sports bring a higher level of physical activity in the sportsman’s life and help to be aware of nutrition, exercise, and health [1].

Intense sports may cause muscular injuries and fatigue. Muscle damage or injuries are mostly attributed to an increase in exercise-induced oxidative stress that causes a decline in skeletal function. It is well known that exercise is the key element in sports to maintain physical strength. However, intensive endurance exercises can lead to an upsurge in oxygen consumption, production of reactive oxygen species (ROS), inflammation, ischemia-reperfusion injury, and white blood cell activation [2]. These physical exercise-related issues cause a decrease in sportsman’s performance and initiate other health problems.

Considering all these factors, sports science needs an effective and easy-to-use medicine or therapeutic regimen to combat athletes’ health issues. Herein, molecular hydrogen is recommended because of its radical scavenging, and anti-inflammatory properties.

This article will elucidate the importance of molecular hydrogen as medicine in sports. Here, we will start with learning about molecular hydrogen and its biological features.

Molecular hydrogen

Molecular hydrogen (H2) is a newly emerged treatment strategy that is found effective against several diseases and is also widely adopted by healthy people.

Hydrogen, a therapeutic gas with no taste and odor offers several biological and therapeutic effects on numerous illnesses ranging from acute illness involving ischemia-reperfusion injury to chronic diseases namely neurodegenerative, rheumatoid arthritis, and metabolic diseases [3, 4]. Besides this, hydrogen is non-toxic and safe gas for therapeutic even at high concentrations. It quickly diffuses into tissues, crosses different tissue barriers i.e., the blood-brain barrier, and penetrates several organelles [5-7].

H₂ also impedes reactive oxygen species (ROS) frequently produced in living systems, a characteristic that contributes to its antioxidant potential. Thus, it is recommended for the treatment of diseases linked to oxidative stress [8, 9]. Likewise, hydrogen is suggested as sports medicine because athletes or sportsmen deal with sports injuries i.e., muscle damage, often due to extensive oxidative stress and inflammation caused by intense exercises, and they opt for maintaining physical fitness.

Molecular hydrogen is employed in therapeutics in different ways namely oral administration in form of hydrogen-rich water (HRW) or as hydrogen tablets, inhalation of hydrogen gas (HI), and injection as hydrogen-saturated saline. The concentration of hydrogen gas in tissues depends on the delivery route and the organ type after the exogenous supply [10]. We will mainly focus on the inhalation method for hydrogen gas use in sports.

Molecular hydrogen as medicine in sports

In the previous two decades, molecular hydrogen has evolved as an effective treatment regimen due to its anti-inflammatory, antioxidant, and anti-apoptotic effects illustrated in various animal disease models and human studies [11]. These characteristics make hydrogen therapy an attractive and promising agent in sports medicine. However, the significance of hydrogen gas utilization in sports is mainly attributed to its antioxidant effect. Because intensive and exhaustive physical exercise causes the overproduction of reactive oxygen species (ROS) and free radicals that facilitate tissue damage [12]. Therefore, using an effective antioxidant agent can help in diminishing oxidative and other cellular stresses. Moreover, it can relieve ROS-related disorders such as inflammation, fatigue, and micro-injury and thus help improve their fitness.

Hydrogen gas therapy is suggested as an effective and innovative therapeutic strategy for sports injuries and exercise-induced oxidative stress with an adding potential for improving exercise performance in athletes [13].

Recent studies have also indicated molecular hydrogen as an alkalizing agent that can also affect cell signaling. Because of the identification of these recent mechanisms of action, the therapeutic application of molecular hydrogen has been extended in clinical medicine even further. In addition, hydrogen therapy trials for sports injuries are in progress and exhibiting favorable results [14].

We will summarize here the action mechanisms of hydrogen gas as sports medicine for eliminating harmful oxidative stress, inflammation, and resulting muscle injuries. Moreover, we are going to highlight its use in increasing overall athletes’ performance.

Molecular hydrogen for exercise-induced oxidative stress

Reactive oxygen species (ROS) are produced within the body as a result of the oxygen consumption through respiration in our daily lives [7]. These reactive molecules are eminent for performing a dual role as both detrimental and beneficial species. ROS plays a significant role in regulating cell homeostasis and molecular signaling under normal physiological circumstances [15].

Besides, exercise-induced excessive production of reactive oxygen species and decreased antioxidant defense systems play a crucial role in skeletal muscle contractile dysfunction that leads to fatigue and muscle weakness. Current studies continue to explore the underlying mechanisms through which oxidants affect skeletal muscle contractile characteristics while investigating therapeutic interventions capable of mitigating muscle damage induced via oxidative stress [12]. Considering this, hydrogen is suggested as the most promising candidate for athletes suffering from damaging oxidative stress due to its low molecular weight and high tissue penetrating ability to scavenge reactive oxygen species [8].

Also, H₂ can diffuse quickly into tissue and scavenge toxic ROS because of its low molecular weight [8], making it a model candidate for athletes suffering from harmful oxidative stress.

There are only limited studies that describe the potential of molecular hydrogen therapy in relieving exercise stimulated oxidative and cellular stress in in vivo and clinical settings. Thus, there is a dire need to explore the antioxidant capacity of hydrogen gas in sports-related health problems to validate its use as a medicine.

Moving forward, oxidative stress is also associated with the production of inflammatory proteins as it regulates cell responses. Therefore, the anti-inflammatory role of hydrogen gas inhalation should be extensively evaluated to verify its use in the sports field.

Hydrogen mitigates exercise-induced inflammation

Physical exercise is reported to induce inflammation that may either be beneficial in the case of regular exercise or be harmful when intense exercise is performed by inexperienced individuals [16]. Molecular hydrogen gas has emerged as a powerful therapeutic tool with potent anti-inflammatory, anti-apoptotic and antioxidant properties, proven against several physiological conditions.

Many studies have explored the positive anti-inflammatory effects of hydrogen gas in animal models. A recent study has investigated the therapeutic potential of molecular hydrogen gas against acute exercise-generated inflammation in the hippocampus of rats. Hippocampus is the part of the brain, most sensitive to inflammation. In this experiment, rats were administered two gas formulations: one with hydrogen (2%) and the other without hydrogen gas, while running on a sealed treadmill. The hippocampal samples were collected for analysis after 3 hours of exercise. The results showed that hydrogen gas significantly reduced exercise induced hippocampal inflammation in rats. Detailed analysis revealed that hydrogen declined the pro-inflammatory cytokines (IL-6 and TNF-α) and increased anti-inflammatory proteins (IL-10), thus exhibiting a potent anti-inflammatory effect [17].

Like this, molecular hydrogen’s anti-inflammatory effect was investigated to relieve inflammation induced by acute physical exercise. Rats ran on a closed treadmill with 80% of their highest running velocity while inhaling 2% hydrogen gas. Hydrogen gas was found to reduce inflammation produced through exercise. Low levels of inflammatory cytokines were detected in the plasma of the experimental group (H₂) compared to the control. Furthermore, attenuation of cellular and oxidative stress was observed in molecular hydrogen-administered rats [18]. Besides these, the putative anti-inflammatory role of hydrogen gas against physiological conditions i.e., physical exercise is still not well elucidated. However, these studies show that hydrogen has a strong potential to mitigate inflammation and treat related health conditions. Further, it can be studied in clinical settings to support its use as a medicine in sports.

Molecular hydrogen for sports injuries

Sportsmen and athletes live an active lifestyle. They opt for intense and endurance exercises to maintain their physical fitness and overall performance. However, these intense and exhaustive physical exercises lead to the accumulation of reactive oxygen species, inflammation, and apoptosis, particularly in inexperienced individuals. This exercise-induced factors then contribute to skeletal muscle damage and many other sports injuries. This may cause decrement in their performance and affect their career. Therefore, they need a regular medicine or supplement that can alleviate the harmful effects of exercise and help in effective recovery from injuries.

Hydrogen gas administration has been shown to ameliorate muscle injuries due to its promising antioxidant, anti-inflammatory, and anti-apoptotic activities. Recently, a research used hydrogen gas inhalation therapy to relieve exercise induced skeletal muscle injury. Rats were administered hydrogen gas while exhaustive running on the sealed treadmill. Hydrogen gas not only reduced the upsurged expression levels of IL-6 and TNF-α but also blunted the activation of the NF-κB gene. In addition, it also alleviated inflammation, oxidative stress, and apoptosis and thus exerted protective effects against muscle damage caused by intense exercise [19]. In addition, molecular hydrogen therapy is reported to reduce the delayed onset muscle soreness DOMS after eccentric exercises [20]. This shows hydrogen therapy can exert protective effects and prevent and heal muscle injuries in athletes.

Hydrogen therapy improves athlete’s performance

Besides combating, oxidative stress, inflammation, and muscle damage, molecular hydrogen is reported to enhance the endurance and overall performance of athletes. Many studies have been designed and carried out to explore hydrogen as an effective sports medicine.

Studies indicate that molecular hydrogen therapy can help athletes maintain and increase their performance. Such as, research showed that pre-exercise administration of molecular hydrogen can alleviate performance decline during repeated sprints in soccer players by diminishing fatigue [21]. In addition, another randomized, double-blind, pilot scale study investigated the effect of hydrogen inhalation on serum hormone levels, inflammation profiles, and exercise performance results of young men and women. hydrogen gas was administered for seven days. The results showed the ergogenic properties of hydrogen gas in healthy individuals. It exhibited significant enhancement in their physical performances [22]. However, further detailed studies are suggested to promote it as a sports medicine.

Interestingly, the administration of molecular hydrogen in judo athletes is reported to reduce post-exercise heart rate and blunt lactate response during the recovery period [23]. Additionally, pre-exercise hydrogen therapy is also shown to mitigate exercise induced acidosis in female athletes [24].

Furthermore, molecular hydrogen exerts a cytoprotective effect on the body to improve exercise performance. A study conducted on eight physically active men suggested that hydrogen inhalation during the recovery period after exercise may ameliorate overall exercise performance by diminishing oxidative stress [25].

All these palpable studies indicate the robust potential of molecular hydrogen as an effective treatment or medicine in sports. However, the number of studies is limited in this field. So, to favour its use as sports medicine, researchers and sports authorities should come together to realize athletes’ problems and accordingly design comprehensive studies both in vivo and in clinical settings.

 

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