A review of the literature affirms that acute alterations in substrate availability effectively moderate exercise response. Furthermore, when these alterations are continued, they ultimately drive the development of phenotypic characteristics common to trained athletes. It has been demonstrated that “low carbohydrate” diets may augment this capacity. However, dietary carbohydrate restriction during training has generally not resulted in enhanced exercise performance in a research testing or competitive environment. Further, lower carbohydrate diets may have a reciprocal effect on lipid availability. Diets that are “low carbohydrate” but high in fats have been linked to insulin resistance and consequent health risks. Therefore, research is still needed to better quantify carbohydrate and lipid intake and intervention periods, especially when paired with exercise, to optimize skeletal muscle adaptations. Future investigations should also focus on the timing and pattern of protein intake to identify the most appropriate and practical supplementation protocols, as well as to identify how antioxidants and phytochemicals work at the cellular level to mediate responses.

Limitations in the interpretation of study comparisons include different training modes, number of training sessions, and intervention times, as well as the multiple biologic activities that were not all assessed.