Nutritional supplements are very popular especially among athletes although some studies show either controversial or even negative results. However, whey protein and creatine seem to have positive effects on muscle size, strength and athletic performance without major adverse effects and high costs. Most studies have shown that supplementation of whey protein can enhance muscle growth in response to resistance training. Some studies also suggest that whey may enhance recovery from heavy exercise and possibly decrease muscle damage and soreness. Creatine supplementation increases the intracellular pool of phosphocreatine in skeletal muscle. Phosphocreatine provides a reserve of energy to rapidly regenerate ATP, which is consumed as a result of muscle contraction. Creatine has been studied in hundreds of clinical trials and has shown benefits including increased muscle strength, power and size.