What is creatine?

What is creatine?

Welcome back to All Things Running with Sonja & Jen. Today Jen is going to talk about Creatine which seems to be having a moment again. It is important to understand what it is and how it is used.

Creatine is created by the body in response to exercise. Creatine is a naturally-occurring substance that's found in meat and fish, and also made by the human body in the liver, kidneys, and pancreas. It is converted into creatine phosphate or phosphocreatine and stored in the muscles, where it is used for energy.

There are 3 Energy Systems:

1. Anaerobic Alactic (ATP-CP) Energy System (High Intensity – Short Duration/Bursts)

2. Anaerobic Lactic (Glycolytic) Energy System (High to Medium Intensity – Uptempo)

3. Aerobic Energy System (Low Intensity – Long Duration – Endurance)

One of the ways that this ATP supply is regenerated is through the molecule creatine phosphate (or phosphocreatine). In the process of regeneration of ATP, creatine phosphate transfers a high-energy phosphate to ADP. The products of this reaction are ATP and creatine.

Creatine-P helps maintain a constant concentration of ATP in muscle during sudden bursts of exercise that would otherwise deplete ATP concentration in the cell.

ATP - adenosine triphosphate is the primary molecule of energy for human movement, or exercise. When our body is at rest, we have a small store of ATP, enough for a few seconds of intense exercise performance (e.g. 5 second max sprint effort, or a vertical jump). This ATP is replenished via another key molecule - phosphocreatine (PC) which can also be referred to as creatine phosphate.

Energy from this system is supplied very quickly, but lasts less than 10 seconds. The body must rest in order for ATP stores to be replenished. This energy system does not rely on nutrition - meaning we do not get the molecules by breaking down food, but synthesize them ourselves. However, creatine supplementation may enhance the PCr system. Additional energy systems are available for more sustainable energy production as exercise duration increases, all of which ultimately produce ATP.

What studies show.

If the body synthesizes the CP system then the question of whether or not to supplement is not clear and will depend on the events in which you participate.

Most studies, however, have noted only a small increase in creatinine levels even with doses ≈20 g/day. Although taking creatine may increase creatinine levels, long- and short-term studies have found that creatine doses ≤10g/day don't impair kidney health in people with healthy kidneys.

When you stop taking creatine, your body will resume its normal production of creatine. You may experience a decrease in strength, endurance, and performance, but this difference likely won't be drastic. A proper diet, structured training routine, and recovery can support your training goals even without creatine.

Who is taking it?

Creatine might benefit athletes who need short bursts of speed or increased muscle strength, such as sprinters, weight lifters and team sport athletes.

While taking creatine might not help all athletes, evidence suggests that it generally won't hurt if taken as directed. Although an older case study suggested that creatine might worsen kidney dysfunction in people with kidney disorders, creatine doesn't appear to affect kidney function in healthy people.

When used orally at appropriate doses, creatine is likely safe to take for up to five years. As with any dietary supplement, it's important to choose a product that follows recommended manufacturing practices and subscribes to third-party testing to ensure the product's quality.

Side effects

Creatine can cause weight gain, generally as lean body mass. People who have low levels of creatine — such as vegetarians — appear to benefit most from creatine supplements.

Although some there are claims about creatine’s side effects and safety issues, none of them are currently supported by current research. Earlier studies from the 90’s had concern about the supplement and its impact on the liver & kidney’s.

Regular diet vs Supplement

A regular diet and natural creatine levels do not typically maximize muscle stores of this compound. The average stores are about 120 mmol/kg in someone who weighs 154 pounds (70 kg), but creatine supplements can elevate these stores to around 160 mmol/kg. During high intensity exercise, the stored creatine helps your muscles produce more energy. This is the main reason that creatine enhances exercise performance. Once you fill your muscle’s creatine stores, any extra is broken down into creatinine, which is metabolized by your liver and released in your urine.

Do I take it?

I don’t personally take a supplement as my body’s natural CK levels are optimized. My body also has naturally high liver enzymes that border on being too high. This can all be attributed to the training that I do as a middle distance runner. It is important to know what your levels are before you begin any supplementation. I use Inside Tracker to monitor all my performance blood markers. I get tested at least 1-2 times per year. These numbers are always elevated when I get my blood drawn after high intensity workouts which happens to be the case year round. So I consider my results with that in mind and always consult my doctors if I have questions.

Sonja and Jennifer are sharing their personal experiences. This is being provided for informational purposes only. We are not giving medical advice and you should always consult your own doctor for advice related to your own health.