What is inosine and why do athletes need it?

What Is Inosine?

Inosine is a natural chemical compound consisting of the purine base hypoxanthine and the sugar ribose. The chemical formula for inosine is C10H12N4O5. Inosine, a nucleoside present in all living cells, plays a significant role in purine biosynthesis, gene translation, and RNA modulation.

The first mentions of inosine and inosinic acid in scientific articles date back to the 19th century. Its molecular and crystal structures were identified between 1965 and 1970.

Inosine is a component of purine nucleotides, participates in metabolic processes, and is used for the synthesis of other nucleotides—in particular, adenine and guanine—which are components of nucleic acids (DNA and RNA) and are essential for the storage and transmission of genetic information.

Inosine plays an active role in energy production and energy metabolism. It is one of the forms of adenosine, which is part of the adenosine triphosphate (ATP) molecule—the primary source of energy for many processes in the body, including muscle contraction, the transmission of nerve impulses, and cell reproduction. Inosine increases oxygen delivery to muscle tissue, improves cognitive function, supports cardiovascular health, and reduces feelings of fatigue.

Inosine’s ability to improve coronary blood flow is used for the prevention and treatment of ischemic heart disease, arrhythmias, myocardial dystrophy, and heart defects. Inosine can improve liver function in cases of chronic liver disease and alcohol intoxication. Recent studies have also revealed its anti-inflammatory, immunomodulatory, and neuroprotective effects.

Benefits of inosine for the body:

• replenishes the body’s energy reserves depleted during physical activity;
• contributes to the replenishment and metabolism of glucose in the blood;
• improves blood circulation and heart function;
• stimulates and accelerates redox processes;
• supports and restores liver function;
• promotes efficient muscle function;
• normalizes tissue respiration;
• promotes tissue regeneration;
• boosts immunity and speeds up recovery from illness.

Which foods contain inosine

Inosine is produced during the metabolism of purines found in proteins. Accordingly, animal-based foods contain the highest amounts of inosine:

• beef and pork dishes, and in high concentrations in broths and stocks;
• fish and seafood—salmon, tuna, mackerel, sardines, mussels, shrimp, and oysters;
• poultry: chicken, turkey, and duck;
• eggs, especially egg yolks;

Legumes, peas, and lentils also contain a certain amount of inosine.

The Benefits of Inosine for Athletes

Inosine’s role in metabolic processes and energy production makes it an important component of sports nutrition.

Why Athletes Need Inosine

Physical activity requires significant energy expenditure; replenishing this energy via ATP involves increased transport of phosphates and oxygen into the muscles. AMP and ADP (adenosine monophosphate and adenosine diphosphate) play a key role in this process; their main component is adenosine (inosine, riboxin). The use of ATP energy during physical exertion increases the demand for adenosine. Therefore, a constant supply of adenosine is essential for athletes in all sports. Inosine supplements are used to improve the transport of oxygen and phosphates into muscle cells, replenish energy reserves depleted during physical exertion, increase endurance, and accelerate recovery after workouts.

Improves endurance and physical performance

Inosine promotes the active production of ATP molecules, which are the primary source of energy for muscles during physical exertion. By increasing the amount of energy muscles need to perform prolonged or intense exercises, inosine enhances overall physical endurance and performance.

Inosine also helps reduce lactic acid levels, which build up in the muscles and cause fatigue. This energy support increases endurance, allowing you to train longer and, consequently, improve your performance and athletic results.

Improves oxygen delivery to muscles

Inosine activates mechanisms that help dilate blood vessels and improve blood circulation, promoting oxygen saturation in tissues. When supplied with sufficient oxygen, muscles work longer and more efficiently, without feelings of fatigue or discomfort.

Supports the cardiovascular system

Inosine improves blood circulation and has a positive effect on the cardiovascular system, reducing the strain on the heart during physical exercise.

Inosine supports the heart’s ability to pump blood efficiently, ensuring a more stable supply of oxygen and nutrients to organs and muscles. This effect allows athletes to maintain high-intensity workouts for longer periods without the risk of overloading the cardiovascular system.

Accelerates post-workout recovery

Inosine reduces inflammation in tissues and alleviates muscle soreness resulting from microtraumas sustained during physical activity. It stimulates the regeneration of muscle fibers, which helps speed up the recovery process and allows you to return to training without pain or fatigue.

Supports the immune system

Prolonged high-intensity training weakens the immune system, increasing the risk of illness. Inosine helps maintain normal immune system function and strengthens immune cells, such as T-lymphocytes, which improves the body’s ability to fight infections and reduces levels of stress hormones that can weaken immunity. This allows athletes to avoid illness and stay healthy even during intense workouts.

Who should take inosine?

Since ATP provides energy to the muscles and its levels are particularly important during intense workouts, inosine is beneficial for both strength training and sports where endurance and speed are key.

Aerobic sports (running, swimming, cycling)

Aerobic sports require high energy expenditure and great endurance. Inosine supports energy and endurance and helps maintain a high level of intensity over a long period of time, which is important in sports that require the ability to sustain prolonged exertion, such as long-distance running, marathons, or cycling races.

Inosine also supports cardiovascular function and reduces the strain on the heart during prolonged aerobic exercise. Additionally, inosine promotes faster recovery, which is important for athletes who frequently train for endurance and need to quickly replenish their energy reserves.

Strength sports (bodybuilding, powerlifting)

By improving energy metabolism in muscles and ligaments, inosine reduces the likelihood of overloading and excessive strain on muscle structures. This is especially important for bodybuilders and powerlifters who perform intense strength exercises, where rapid energy recovery is key to achieving maximum results.

Endurance in team sports (soccer, basketball, hockey)

The benefit of inosine for sports where endurance is just as important as speed and concentration is that it helps maintain high energy levels over long periods of time. This is especially relevant for soccer, hockey, basketball, and other team sports, where players must maintain high intensity throughout the entire game without losing speed or focus.

Inosine helps reduce fatigue, increase concentration, and improve reaction time, allowing athletes to execute quick tactical maneuvers and respond promptly to changing situations. As a result, players can maintain high performance until the end of the game, which is crucial for team success.

How to Take Inosine

As a pharmaceutical drug, inosine is available in tablets and as a solution for injection. For use in sports, inosine is available in 0.5-gram gelatin capsules combined with glucose or fructose.

Inosine Plus Vansiton in capsules has a positive effect on metabolic processes in the myocardium, improves the myocardium’s energy balance, enhances coronary blood flow, plays a direct role in glucose metabolism and replenishment, stimulates redox processes, and normalizes tissue respiration.

Recommended for improving performance and endurance during prolonged periods of maximum physical exertion.

Directions:

Take 2–3 capsules 1 hour before training.

Daily Intake for Athletes

The daily intake of inosine for athletes may vary depending on individual needs, type of physical activity, and goals. The standard dosage for athletes is 3–6 mg per kilogram of body weight. For a person weighing 70 kg, the daily dosage of inosine will range from 210 to 420 mg. A dosage within this range helps improve endurance and recovery speed without overloading the body.

The daily dose can be adjusted depending on individual needs, fitness level, and type of physical activity. If an increase in the daily dose is necessary, the supplement should be divided into 2–3 doses throughout the day.

When to Take Inosine

Inosine is a single-ingredient supplement taken before a workout to help prepare the body for physical exertion. It is best taken 30–60 minutes before your workout.

Best Combinations of Inosine with Other Supplements

To improve workout results, inosine can be combined with other sports supplements.

Creatine helps improve endurance and strength, and combining it with inosine will have a positive effect on ATP synthesis and the rapid restoration of energy reserves.

Beta-alanine, when combined with inosine, helps reduce fatigue during workouts, improve endurance, and extend workout duration without reducing intensity.

BCAAs with inosine will help boost energy levels, reduce fatigue, and speed up muscle recovery after workouts.

L-carnitine effectively burns fat and converts it into energy. When combined with inosine, L-carnitine can improve workout performance and speed up recovery.

The amino acid citrulline helps increase blood flow and reduce fatigue during workouts. Combining citrulline with inosine can improve oxygen delivery to the muscles, boost energy levels, and increase endurance during aerobic and strength training.

Caffeine and inosine can “work together” because they have different mechanisms of action. Inosine promotes the production of ATP, which provides the body with a steady supply of energy, while caffeine affects the central nervous system, reducing fatigue and improving concentration. Caffeine also stimulates the release of adrenaline, which boosts physical performance and the ability to withstand intense exertion. The combination of these substances can help athletes maintain energy and focus during long workouts or matches, especially in sports where speed and endurance are critical.

However, it is important to remember that excessive caffeine consumption can cause side effects such as nervousness, insomnia, or tachycardia. At the same time, the combination of inosine and caffeine in high doses can affect the body in different ways, so it is important to monitor the dosage of each of these substances.

B vitamins (specifically, vitamins B6, B12, and folic acid) are important for energy metabolism in the body and also promote better absorption of inosine. They support energy metabolism and the nervous system, and also aid in recovery after physical exertion.

Contraindications and Side Effects

Inosine is considered safe and does not cause side effects when taken at the recommended dosage. If the dosage is significantly exceeded, the following side effects may occur:

• allergic reactions: skin rash, itching, hives;
• increased nervous excitability;
• sleep disturbances;
• digestive discomfort, bloating, nausea;
• increased levels of uric acid in the blood.

With long-term use, tachycardia, hypotension, exacerbation of gout, general weakness, headaches, and dizziness may occur.

Contraindications for taking this supplement include:

• allergic reactions or hypersensitivity to the supplement’s ingredients;
• chronic kidney disease, renal failure;
• a tendency to develop kidney stones;
• confirmed gout (inosine is a source of purines, which increase uric acid levels in the body).

The use of inosine supplements by women during pregnancy and lactation is recommended only after consulting a doctor.

Scientific sources: