Global metabolic stress of isoeffort continuous and high intensity interval aerobic exercise: a comparative 1H NMR metabonomic study

The overall metabolic/energetic stress occurring during an exercise-bout is proposed as the main driving force for long-term training adaptations. Continuous and high-intensity interval exercises (HIIE) are currently prescribed to acquire the muscular and metabolic benefits of aerobic training. We applied 1H NMR-based metabonomics to compare the overall metabolic perturbation and the activation of individual bio-energetic pathways of three popular aerobic exercises matched for effort/strain. Nine men performed continuous, long-interval (3min-bouts), and short-interval (30s-bouts) exercise-bouts under isoeffort conditions. Blood was collected before and after exercise. The multivariate PCA and OPLS-DA models showed a distinct separation of pre- and post-exercise samples in three protocols. The two models did not discriminate the post-exercise overall metabolic profiles of three exercise types. Analysis focused on muscle bio-energetic pathways revealed an extensive up-regulation of carbohydrate-lipid metabolism and TCA-cycle in all three protocols; there were only few differentiations among protocols in post-exercise abundance of molecules when long-interval bouts were performed. In conclusion, continuous and HIIE exercise protocols, when performed with similar effort/strain, induce comparable global metabolic stress despite their marked differences in work-bout intensities. This study highlights the importance of NMR-metabonomics in comprehensive monitoring of metabolic consequences of exercise training in blood of athletes and exercising individuals