Creatine & Muscle Weakness

Creatine is an amino acid -- the building block of protein -- that your body makes and that is also present in food. Your body converts creatine and stores it in your muscles for later use. When you perform activities that require short, intense bursts of strength or speed, such as weightlifting or sprinting, your body converts creatine into energy for use. These body mechanics are some of the reasons why athletes and those with conditions that cause muscle wasting take creatine supplements to reduce muscle weakness.

Creatine Levels

While the body makes creatine, it is also present in high-protein foods like meat and fish. If you eat a very high-protein diet, it is possible that your creatine levels may be anywhere from 10 to 30 percent higher than those who do not. Men also tend to have higher levels of creatine than women because they typically have more muscle mass. If you have low creatine levels, you may experience muscle weakness as a side effect. These low levels are often associated with an underlying medical condition, however. For example, patients with kidney disease or muscular dystrophy often have low creatine levels in their blood.

Testing

If you suspect your creatine levels are low, your physician may recommend blood testing. The blood test measures for creatinine, a substance produced when your body breaks down creatine. The level of creatinine can tell your physician how much creatine is being converted for use. Physicians may use this as one of many tests to diagnose conditions like kidney disease.

Athletic Performance

Athletes often use creatine supplements to improve athletic performance. While studies seemed to be mixed on the overall results, some studies have shown that taking creatine can improve strength and muscle mass in athletes engaging in activities that require short bursts of speed or strength, according to the University of Maryland Medical Center. However, endurance athletes like long-distance runners may not experience similar benefits.

Medical Conditions

MedlinePlus ranks creatine as "possibly effective" for reducing muscle weakness in patients with certain medical conditions. This includes patients with Parkinson's disease, heart failure, muscular dystrophy and gyrate atrophy, an eye disease that affects sight. However, patients tend to react differently to creatine, meaning it may not always prove effective in treating these conditions.

Safety

Always check with your physician before taking creatine supplements as they can interact with medications and supplements like diuretics and ephedra. While creatine is generally considered safe when taken in the recommended doses, excess amounts may cause stomach upset and affect your kidneys, because the kidneys are responsible for filtering creatine by-products.