Creatine

Creatine is one of the most popular nutritional ergogenic aids for athletes, used for improving muscle mass, performance, and recovery. ^{[1] [2]} Creatine is also an essential brain compound that plays a key role in brain bioenergetics. ^{[3] [4]}

Creatine supplementation increases intramuscular creatine concentrations, which may help explain the observed improvements in high-intensity exercise performance leading to greater training adaptations. ^[2] Creatine monohydrate supplementation enhances short-term performance by increasing intramuscular phosphocreatine stores, which aid in ATP resynthesis during intense muscle contractions. ^[5] Creatine plays a critical role in cellular metabolism, particularly during metabolically stressed states, and increasing its availability in tissue may enhance cellular metabolism. ^[6]

Creatine supplementation is relatively well tolerated, and short- and long-term supplementation has been reported as safe and well-tolerated in healthy individuals and in a number of patient populations ranging from infants to the elderly. ^{[1] [2]} A systematic review and meta-analysis found that creatine supplementation did not significantly alter serum creatinine levels or plasma urea values, indicating it does not induce renal damage in the studied amounts and durations. ^[7] In a meta-analysis of randomized controlled trials, creatine supplementation improved measures of memory compared with placebo, with a significant improvement in older adults aged 66 to 76 years. ^[4] A systematic review of randomized controlled trials concluded that oral creatine administration may improve short-term memory and intelligence or reasoning of healthy individuals, suggesting potential benefit for aging and stressed individuals. ^[3] A meta-analysis reported that creatine supplementation

Accumulating evidence suggests that creatine supplementation produces a variety of beneficial effects in older and patient populations, and it has been concluded that creatine has several health and therapeutic benefits throughout the lifespan. ^{[1] [6]} Creatine has potential to improve cognitive processing especially in conditions characterized by brain creatine deficits, including those induced by acute stressors such as sleep deprivation or by chronic conditions such as aging and Alzheimer's disease. ^[9] Beyond athletics, creatine may mitigate muscle wasting in conditions such as sarcopenia and cachexia and support neuroprotection in neurodegenerative diseases such as Parkinson's and Huntington's. ^{[5] [2]}