Different types of physical activity have distinct consequences for endogenous metabolism
Lately, we have posted an article about the biochemistry of obesity. Confirming which pathways are affected by an increasing BMI is complicated by the fact that not every pound or kilogram is the same. For example, the ratio of muscle mass to fat mass can differ considerably between two individuals with the same BMI. Metabolism is regulated differently in a trained muscle compared to an untrained one. Understanding these differences could be the key to improving knowledge about obesity, inactivity, BMI, and related diseases, and point to possible exercise-based interventions.
Competitive athletes are extreme phenotypes, conditioned by a certain type of physical exercise. This makes them ideal subjects for a comparative study of metabolic variation. A recent study spearheaded by the Technical University in Munich investigated the metabolic profiles of sprinters, endurance athletes, and bodybuilders, in comparison to untrained controls. There were clear metabolic differences between each group. Interestingly, both endurance athletes and bodybuilders separated more clearly from untrained controls than sprinters did.
Bodybuilders were characterized by lower levels of branched-chain amino acids (BCAA), which in excess have been associated with insulin resistance. Endurance athletes, on the other hand, showed a marked increase in the activity of carnitine-palmitoyl-transferase I (CPT-1), an important regulator of mitochondrial fatty acid oxidation. This hints at potential benefits for diseases driven by mitochondrial dysfunction. The study also revealed changes in metabolite concentrations at rest and after exercising.
Although this study focused on extreme phenotypes with years of training, knowing which metabolites differentiate these groups could start to explain how different modes of lifestyle intervention might affect patient outcomes. More research is needed to achieve truly personalized lifestyle therapies based on metabolic parameters, such as the long-term effects of training in less extreme phenotypes or in specific disease states.
For another recent article on the metabolic effects of physical activity, check out the blog post “The metabolic cost of a marathon: fitness matters”
Schranner, D., Schönfelder, M., Römisch-Margl, W., Scherr, J., Schlegel, J., Zelger, O., Riermeier, A., Kaps, S., Prehn, C., Adamski, J., Söhnlein, Q., Stöcker, F., Kreuzpointner, F., Halle, M., Kastenmüller, G. and Wackerhage, H.: Physiological extremes of the human blood metabolome: A metabolomics analysis of highly glycolytic, oxidative, and anabolic athletes.(2021) The Physiological Society | https://doi.org/10.14814/phy2.14885