Aerobic Fitness May Trump Strength for Metabolic Health

Endurance affects metabolism substantially more than muscular strength does, a new study suggests.



Stamina may trump strength for improving metabolic health, according to an interesting and provocative new study of the molecular effects of different aspects of fitness. The study, which was published in August in JAMA Network Open, finds that people’s aerobic endurance — or lack of it — can influence their metabolisms more potently than their muscular weakness or might, a result with implications for anyone wondering which types of exercise could be most beneficial for health.

Our metabolisms are, of course, massively complex, encompassing the myriad biochemical reactions that transform calories into energy and keep our cells nourished. But many standard measures of metabolic health, such as blood sugar or cholesterol levels, are broad, providing an overview of the state of our interiors, but little detail.

So, in recent years, a new field of science, called metabolomics, has begun trying to better parse our metabolisms by using high-tech tools to enumerate the metabolites in our tissues. Metabolites are any molecules involved in metabolic reactions and include everything from proteins and fatty acids to minute, sub-particles of different forms of cholesterol.

By comparing the types, amounts, ratios and interactions of all of the metabolites in the blood of people with or without conditions such as heart disease, metabolomics researchers have been developing granular schematics of desirable — and detrimental — metabolite patterns. These molecular “signatures” of metabolic diseases eventually should help researchers to better diagnose metabolic problems and start teasing out how, at this molecular level, people’s metabolisms can be reshaped by nutrition or obesity or other issues.


Much of the original metabolomics research centered on illness, however, prompting some scientists recently to wonder about the blood signatures of sturdy good health and, in particular, of fitness. Fit people tend to have much lower risks for metabolic problems than the inactive. But whether that fitness is reflected in the patterns of metabolites in their blood and, if so, what those patterns might tell us about how physical activity molds metabolisms, remained largely unknown.

So, recently a group of Scandinavian researchers set out to learn more. First, for a