Creatine is commonly used to support high-intensity, short-duration performance (sprinting, resistance training), strength gains, and training volume. It works by increasing muscle phosphocreatine stores, helping regenerate ATP more rapidly during intense effort. Some individuals experience improvements in reps, power output, and recovery, though responses vary based on sleep, nutrition, training design, and genetics. A loading phase is not mandatory; many achieve benefits with consistent daily dosing. Typical side effects are gastrointestinal discomfort and water retention. People with kidney disease, a single kidney, older age with multiple comorbidities, or kidney-stressing medications should consult a clinician before use.