Benefits of Phosphocreatine in Athletics

Can supplementation build muscle mass and strength?

Track sprinter

Matilde Gattoni / arabianEye / Getty Images

Phosphocreatine, also known as creatine phosphate, is a naturally occurring organic compound that facilitates muscle contractions. It is found in muscle tissues and enables powerful bursts of energy lasting for no more than 8 to 12 seconds. In the aim to increase muscle mass and strength, athletes will often turn to creatine supplements to amplify this effect.

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 percent to 90 percent 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. Trainers call this "pushing yourself to exhaustion."

How Phosphocreatine Works

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 percent of the creatine will be absorbed by lean muscles and quickly converted into phosphocreatine.

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.

It is for this reason that athletes and bodybuilders will turn to creatine supplements to help build muscle mass. It is presumed that by providing your body with the building blocks of phosphocreatine, you can speed the replenishment of ATP and, in turn, the duration of high-intensity workouts.

Creatine supplements may also help older people who typically experience drops in phosphocreatine from the middle years onward. Unlike performance-enhancing drugs (PEDs) used illegally by athletes, creatine is neither a controlled substance nor banned by major sporting organizations.

Creatine Supplementation

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 its ready availability. 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.

According to a study from Nova Southeastern University in Florida, male bodybuilders given creatine before and after a workout achieved greater gains in fat-free muscle mass and strength after four weeks compared to those who weren't.

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

Dosing and Side Effects

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.

Some 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 needed to determine the long-term safety of creatine.

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

Was this page helpful?

Article Sources

Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.