{"id":"creatine","name":"Creatine","category":"amino_acid","summary":"Creatine monohydrate is the most effective ergogenic aid for increasing high-intensity exercise capacity and lean body mass, supported by over 500 studies including 82 meta-analyses. It works primarily by increasing intramuscular phosphocreatine stores, facilitating rapid ATP resynthesis and cellular hydration. Beyond athletic performance, it shows significant benefits for sarcopenia in older adults, cognitive function during stress, and strength maintenance in certain muscular dystrophies. While universally effective for power and strength, its benefits for pure aerobic endurance are negligible.","evidence_quality":"strong","dosing":"The standard protocol involves a loading phase of 20g/day (divided into 4x5g doses) for 5-7 days to rapidly saturate muscle stores, followed by a maintenance dose of 3-5g/day (or 0.1g/kg of body mass). Alternatively, a consistent dose of 3-5g/day without loading will achieve full saturation within 28 days. For older adults or those with higher muscle mass, the upper end of maintenance (5-10g/day) may be more effective. Creatine monohydrate remains the gold standard form due to superior bioavailability and cost-effectiveness.","timing":"While total daily intake is the primary driver of results, some evidence suggests slightly superior muscle retention when consumed post-workout alongside carbohydrates and protein to leverage insulin-mediated uptake. On non-training days, timing is less critical and can be taken with any meal. For cognitive benefits during sleep deprivation, a single acute dose of 20g has been utilized in protocols.","key_findings":[{"finding":"Creatine increases lean mass by approximately 0.36% per week and strength by 1.09% per week when combined with resistance training.","direction":"positive","study_type":"meta-analysis","pmid":"12433852"},{"finding":"Upper-body exercise shows a significantly larger effect size (ES 0.42) compared to lower-body exercise (ES 0.21) for performance gains.","direction":"positive","study_type":"meta-analysis","pmid":"12945830"},{"finding":"In older adults (65+), creatine significantly increases fat-free mass and improves functional performance in tasks like the chair stand test.","direction":"positive","study_type":"meta-analysis","pmid":"24576864"},{"finding":"Creatine increases muscle strength by 8.47% in patients with muscular dystrophy compared to placebo.","direction":"positive","study_type":"meta-analysis","pmid":"23740606"},{"finding":"High-dose creatine (150mg/kg/day) can worsen muscle pain and impair daily activities in patients with McArdle disease.","direction":"negative","study_type":"meta-analysis","pmid":"25391139"}],"practical_recommendations":["Recommend 3-5g of creatine monohydrate daily for all strength and power athletes to maximize training volume and recovery.","For older clients (60+), emphasize that creatine is a safe and effective tool to combat sarcopenia, but must be paired with resistance training for at least 6 months for maximal lower-body benefits.","Advise athletes training in heat that creatine does not cause dehydration or cramping; it may actually provide a hyper-hydration effect.","Use a loading phase (20g/day for 5 days) only if rapid weight gain and performance shifts are needed within a week; otherwise, 5g daily is sufficient.","Screen clients for metabolic myopathies (like McArdle disease) before recommending high-dose creatine, as it may exacerbate symptoms."],"safety_summary":"Creatine is remarkably safe for long-term use in healthy individuals. The most common side effect is initial weight gain (1-2kg) due to water retention. High doses (150mg/kg) are contraindicated in McArdle disease as they increase myalgia. There is no evidence of kidney damage in individuals with healthy renal function, though those with pre-existing kidney disease should exercise caution. No link to hair loss or dehydration has been substantiated in controlled trials.","interactions":[],"study_count":555,"top_studies":[{"pmid":"1327657","title":"Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation.","year":1992,"type":"clinical-trial","direction":"positive","takeaway":"High-dose creatine loading (20g/day) effectively increases muscle creatine stores, especially in those with lower baseline levels."},{"pmid":"8828669","title":"Muscle creatine loading in men.","year":1996,"type":"clinical-trial","direction":"positive","takeaway":"Athletes can choose between a rapid 6-day load (20g/day) or a gradual 28-day approach (3g/day) to achieve the same muscle saturation."},{"pmid":"28615996","title":"International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, …","year":2017,"type":"review","direction":"positive","takeaway":"Creatine is a safe, multi-functional supplement that enhances performance, recovery, and injury prevention across all age groups and training levels."},{"pmid":"28251287","title":"Nutrition and physical activity in the prevention and treatment of sarcopenia: systematic review.","year":2017,"type":"systematic-review","direction":"mixed","takeaway":"Exercise is the primary driver of muscle health in seniors; nutritional supplements offer limited additional benefit for those who are already well-n…"},{"pmid":"22513923","title":"Treatment for mitochondrial disorders.","year":2012,"type":"meta-analysis","direction":"mixed","takeaway":"There is no clear evidence that common supplements like CoQ10 or creatine provide consistent clinical benefits for mitochondrial disease patients, th…"}],"source_url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC6090881/"}