What is creatine phosphate used for

About 90 percent of the body’s creatine deposits are stored in the skeletal muscle. All living cells need energy. More than any other cells, muscle cells require large amounts of energy when in active use. Creatine helps make this energy more readily available.

How do muscles gain the additional energy?

In the case of short, intense exercises such as sprinting, muscles need lots of energy in the shortest possible time. At the beginning of any such anaerobic exercise (independent of oxygen), the muscles rely on energy sources that are immediately available. These exist in the form of adenosine triphosphate (ATP) and creatine phosphate.

ATP and creatine phosphate act as energy depots (i.e., a kind of battery). They help bridge the time until the biodegradation of glucose (glycolysis), glycogen (glycogenolysis) and fat (lipolysis and fatty acid oxidation) release further energy into the body.

How is energy released into the muscle?

ATP is the energy needed for all biological processes. The ATP molecule has three phosphate groups. If ATP breaks down a phosphate group, the energy released enables  muscle function. What remains is adenosine diphosphate (ADP), which the body converts back to ATP using energy present in food. However, this process takes longer and only produces enough ATP to last for a few seconds. The body can therefore regenerate ATP levels more quickly if the muscle performance required is longer and more intense.

How can creatine support muscle movement?

When a muscle is at rest, about two-thirds of its creatine capacity is available in the form of energy-rich creatine phosphate, which contains an additional phosphate group. Even before the hard-working muscles run low on ATP, the enzyme creatine kinase (CK) transfers this phosphate group to ADP and converts it back to ATP – but only as long as sufficient levels of phosphocreatine are present. This allows the muscles to work anaerobically until the supply of creatine phosphate becomes scarce. During the next resting phase, the creatine that was created is converted to creatine phosphate by the addition of a phosphate group. Once the supply of creatine phosphate has returned to its initial levels, it is then able to provide ATP during the next round of intense physical activity.

What does creatine do?

Creatine is an ideal nutritional supplement for athletes because it promotes the transmission of energy within the cell structure in the form of creatine phosphate. The storage of creatine phosphate in muscular cells can be increased through supplementation with creatine. This improves performance during periods of intense muscle use, which results in increased muscle growth and greater strength. The larger creatine phosphate pool also leads to a faster regeneration of ATP and therefore helps recovery after intensive exercise – at both the amateur and competitive level.

Phosphocreatine, also known as creatine phosphate, is a naturally occurring organic compound that facilitates muscle contractions. It is found in muscle tissues and allows for maximum bursts of energy lasting about 5 to 6 seconds. Athletes often turn to creatine supplements to amplify this effect with a goal to increase muscle mass and strength,

The phosphocreatine energy system refers to the mechanism by which phosphocreatine facilitates muscle contractions. The system starts with the release of a substance known as creatine from the liver into the bloodstream. Around 95% of the creatine will be absorbed by lean muscles and quickly converted into phosphocreatine.

Many bodybuilders and athletes supplement with creatine to enhance their performance in their sport. But creatine supplements may also benefit older adults who experience drops in phosphocreatine from middle age onward. Unlike performance-enhancing drugs (PEDs) used illegally by athletes, creatine is neither a controlled substance nor banned by major sporting organizations.

Phosphocreatine is important because it helps produce a chemical in muscles known as adenosine triphosphate (ATP). ATP is often referred to as the "molecular currency for energy" because of its foundational role in muscle contractions.

While ATP is the chemical that triggers the actual contraction—by activating fibrous proteins in muscles called myosin—very little is stored in muscles. During intense exercise, ATP is used up within seconds and needs to be replenished using phosphocreatine.

Creatine supplements can help build muscle mass by providing your body with the building blocks of phosphocreatine. This helps to speed up the replenishment of ATP and, in turn, the duration of high-intensity workouts.

To understand how phosphocreatine powers maximum bursts of effort, it's helpful to know the difference between aerobic vs. anaerobic contractions.

Muscles use phosphocreatine during the first few seconds of an intense muscle contraction, such as during powerlifting or sprinting. Unlike aerobic contractions, which utilize oxygen to produce energy, phosphocreatine triggers energy without oxygen. As such, it is considered anaerobic.

Anaerobic contractions occur when you are performing a high-intensity exercise at 80% to 90% of your maximum heart rate (MHR). At this level, your oxygen needs will exceed your oxygen supply, and your body will turn to alternative sources of energy, like phosphocreatine, to fuel explosive contractions.

Unlike aerobic contractions that can be sustained by respiration, anaerobic contractions do not last for very long. The generated energy is consumed very quickly, after which you reach an anaerobic threshold characterized by rapid muscle fatigue.

Creatine is an effective supplement to boost performance during high-intensity exercise, particularly when combined with strength training. Supplementing with creatine increases the phosphocreatine stores in your muscles during high-intensity exercise to produce more ATP, leading to gains in lean muscle mass, and enhancing power and strength.

Additionally. creatine supplements may also help to increase the levels of phosphocreatine in your brain. Research shows this may promote brain health and prevent cognitive decline and age-related neurological diseases.

If you're interested in supplementing with creatine to build muscle, you may experience some of the following benefits.

• Boosted exertion: Creatine can help boost total workload or exertion during training sessions, which plays a role in long-term muscle growth.
• Elevated anabolic hormones: Research suggests that creatine may create an increase in hormones like IGF-1 (insulin-like growth-factor1) in young adults, which promotes cellular growth.
• Improved cell hydration and signaling: Creatine can add volume to cells, which may play a role in muscle gain. Other studies have shown that creatine may also increase cell signaling, which can repair muscles and promote growth.
• Minimized protein breakdown: Some older studies have suggested that creatine may be helpful for increasing muscle mass by minimizing the amount of muscle that can potentially be broken down.
• Reduced levels of myostatin: When the protein myostatin is elevated, new muscle growth is impaired. But creatine supplementations can increase the potential for muscular growth.

Although red meat is a natural source of creatine, it isn't concentrated enough to boost phosphocreatine levels in muscles. To effect significant increases, athletes will turn to creatine supplements such as creatine monohydrate or creatine ethyl ester.

Part of the reason for creatine's popularity is that it's readily available. It doesn't require a prescription, and you can find it in drugstores and grocery stores in a variety of formulations including powders, tablets, energy bars, and drink mixes. Although creatine is a natural substance, research suggests that it offers measurable benefits with minimal harm.

A 2018 study published in Nutrients tracked a group of 30 "explosive" college athletes for four weeks to determine whether creatine supplementation during training could enhance their performance. The creatine group exhibited greater muscular strength and reduced muscle damage compared to the control group, and also also showed an improvement in body fat percentages.

In addition, a 2013 study found that male bodybuilders who supplemented with creatine before and after a workout achieved greater gains in fat-free muscle mass and strength after four weeks compared to those who did not supplement.

Similar findings have been seen in female athletes and seniors, although claims that creatine can treat age-related disorders like Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis are often exaggerated.

As with all dietary supplements, creatine supplements are not held to the same rigorous testing standards by the Food and Drug Administration (FDA) as medications. This means the quality of your creatine supplement can vary from one brand to the next. 

The long-term effects of creatine supplementation are still largely unknown, particularly among young people. No matter which age group you fall in, it’s important to seek your doctor’s advice before taking creatine. They may have a recommendation for the appropriate dosage for your physique or suggest an alternative.

While current dosing recommendations are loosely supported by research, many sports nutritionists endorse a daily loading dose of 0.3 grams of creatine per kilogram of body weight for 4 to 6 weeks. Thereafter, you would take a maintenance dose of 0.1 grams per kilogram per day. At this level, creatine supplements are considered safe and effective.

With that being said, when combined with other supplements or taken at exceptionally higher doses, creatine has been known to cause liver, kidney, and even heart damage. Even when used as prescribed, fluid retention and muscle cramps are commonly cited side effects of creatine supplementation. Other research shows that creatine supplementation may cause weight gain and even exacerbate symptoms of anxiety in some people.

Other studies have suggested that the consumption of creatine with protein and carbohydrates may have a greater effect than creatine combined with either protein or carbohydrates alone. Further studies are still needed to determine the long-term safety of creatine.

Due to the lack of quality research, creatine supplements should never be used by children or during pregnancy or lactation.

There's plenty of research to show that supplementing with creatine can enhance athletic performance and increase lean muscle mass. However, keep in mind that dietary supplements are largely unregulated by the FDA, which could affect quality.

If you're interested in trying creatine, talk to your doctor before adding any new dietary supplements to your regimen. They may be able to provide you with the best recommendations to suit your individual needs to help you meet your fitness goals.