Dietary supplements are considered foods whose purpose is to supplement the usual diet. They represent concentrated sources of nutrients or other substances of nutritional or physiological effect. They are intended to correct nutritional deficiencies, support certain physiological functions, or maintain an adequate intake of certain nutrients. They are on the market in the form of liquids, powders, tablets, ampoules, gels or some other methods of application and are considered preparations produced from concentrated sources of nutrients (vitamins and minerals) or other substances with a nutritional or physiological effect on the body. Some of the most commonly used dietary supplements are whey protein, glutamine, bicarbonate, creatine, fatty acids, vitamins and minerals. Dietary supplements should not be considered as a substitute for a proper balanced diet and should not be taken before assessing the nutritional status of the organism. Following the assessment, the athlete should consult with a sports nutritionist about possible corrections in nutritional status. The nutrition supplement plan works with a nutritional supplement based on nutritional findings taking into account numerous factors for each individual athlete such as age, gender, type of activity that dominates training and sports competition, duration of activities, rest time between workouts and many others.