Metabolic fuel utilization during swimming: Optimizing nutritional requirements for enhanced performance

Abstract

Swimming activity is fueled by energy derived from the catabolism of lipids, carbohydrates, or proteins, which ultimately have to be obtained from the diets of fish. This chapter describes changes in the relative use of metabolic fuels available in fish, providing estimates for increasing energy expenditure during different types of swimming conditions. The enzyme AMP-activated protein kinase plays an evolutionarily conserved role during exercise, acting as a fuel gauge in the muscle of fish. Feeding and feed composition may alter swimming performance by changing the cardiovascular capacity and the relative utilization of metabolic fuels. Sustained swimming can enhance the utilization of dietary carbohydrates after a highly digestible carbohydrate-rich meal, sparing the use of protein for muscle growth. Therefore, an optimal diet formulation in combination with an adequate swimming regime may further improve growth rates and feed efficiencies observed in some fish species. Establishing and applying such conditions may imply important advantages for the fish farming industry.