An ergogenic (or ergogenic aid) refers to a training technique, mechanical device, nutritional ingredient, dietary practice, or supplement that improves physical performance or enhances training adaptations. Nutritional supplements are the most commonly used type of ergogenic aid.

A supplement (or other technique) is considered to be ergogenic if it has been shown to acutely (in the short term) improve exercise performance or recovery from a single bout of exercise or if it promotes an improvement in performance (e.g., muscle hypertrophy, strength, power, speed, or endurance) after weeks to months of supplementation.

Some examples of ergogenic aids include creatine, caffeine, carbohydrate loading, protein, and techniques such as massage, and high-altitude training.