Neue Blutuntersuchung verbindet die körperliche Fitness mit Blutbiomarkern, identifiziert Aspartat als Hauptfaktor für die Förderung eines gesünderen Alterns und zeigt, wie gut jemand altert wird

> Researchers first synthesized a single „Body Activity Index“ (BAI) by applying canonical correlation analysis to scores from walking distance, chair‐rise tests, handgrip strength, and balance assessments. This composite physical‐performance metric captures endurance, strength, and coordination in one robust measure. Independently, a „Metabolomics Index“ was derived from blood concentrations of 35 small-molecule metabolites. Across 263 samples from older adults, these two indices showed a Pearson correlation coefficient of 0.85 (p < 1 × 10⁻¹⁹), demonstrating that the molecular signature in blood mirrors the composite measure of physical fitness.

>Aspartate is more than a simple metabolic intermediate: in the brain it also serves as a precursor of neurotransmitters, activating NMDA receptors that are essential for learning and memory. This dual role provides a possible link between physical fitness and cognitive health. Independent studies have shown that low AST and ALT levels in midlife – or an elevated AST/ALT ratio – are associated with increased risk of Alzheimer’s disease and age-related cognitive decline. By demonstrating that physical activity drives dynamic changes in aspartate metabolism and in the plasticity of these two enzymes, the present study points to a molecular bridge between muscle-liver health and brain resilience. These findings suggest a simple message: physical activity helps in preserving strength and mobility, and may also contribute to protecting the brain from dementia through measurable shifts in amino-acid–based signaling pathways.
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>“Physical activity does more than building up muscle mass,“ explains Wolfram Weckwerth: „It rewires our metabolism at the molecular level. By decoding those changes, we can track – and even guide—how well someone is aging“.

[Machine learning and data-driven inverse modeling of metabolomics unveil key processes of active aging | npj Systems Biology and Applications](https://www.nature.com/articles/s41540-025-00580-4)

VO2Max is also a great proxy, as unlike some other metrics, you can’t really fake it