The Role of Supplements in Improving Muscular Strength and Endurance in Professional Soccer Players: A Systematic Review

A proper diet should provide all the nutrients necessary to promote adaptations throughout the training process. Nevertheless, several factors may increase the requirements for energy, vitamins, and minerals. Moreover, the effects of some products on muscle mass and function in athletes are not only related to an improvement in existing nutritional deficiencies. This systematic review aimed to discuss the mechanisms, effects, real ergogenic benefit, when possible, and the optimal use of the most popular nutritional supplements used for improving muscular strength and endurance in soccer players. Results show that vitamin D may be related to hormonal concentration in the blood, while creatine nitrate may be related to an increase in the number of repetitions carried out in training. Despite the latest evidence, new data are needed to elucidate reasons for different responses to these molecules.