Background:
Regular physical activity is known to benefit health but the
long-term effects of specific exercise training on human metabolism
remain incompletely described. In this study, we comprehensively
characterized the blood metabolomes of male athletes with distinct
exercise-adapted metabolic profiles, comparing endurance athletes (n =
11), sprinters (n = 8), and natural body builders (n = 9) as models for
highly oxidative, glycolytic, and anabolic metabolism, respectively.
Methods:
Serum samples of these athletes and a control group of male
untrained individuals (n = 7) were collected both at rest and after
maximum exercise. Using untargeted metabolomics profiling and weighted
correlation network analysis, we examined associations of metabolites
and metabolite modules with athlete groups and their characteristic
traits (e.g., cardiovascular fitness or muscularity).
Results:
Our analyses revealed distinct metabolic signatures for the
different groups: a highly anabolic metabolism was characterized by
lower levels of sulfated steroids; a highly oxidative metabolism by
higher levels of phospholipids; and a highly glycolytic metabolism by
lower levels of sphingomyelins. In response to maximum exercise, 130
metabolites changed across all groups (e.g., N-lactoyl amino acids,
acylcholines, energy metabolites), while 57 metabolites showed
differences in magnitude or direction of change between groups (e.g.,
fatty acid oxidative products, cortisol).
Conclusion:
Our findings demonstrate that exercise-induced adaptations in
metabolism distinctly shape the human serum metabolome and influence the
metabolic response to exercise. These insights are relevant for
diseases driven by dysfunctional metabolism, such as impaired fat
oxidation and dysregulated glycolysis (e.g., diabetes, dementia) and
muscle wasting (e.g., sarcopenia), where our specialized populations may
serve as useful models.