Aerobic endurance, not physical strength, may be the most important factor in improving one's long-term metabolic health, according to a recent study published via the JAMA Network Open.
In the abstract of "Associations of Aerobic Fitness and Maximal Muscular Strength with Metabolites in Young Men," published on Aug. 23, researchers conceded that although high fitness is associated with reduced risk of heart disease and death, it remains unclear how aerobic fitness and muscular strength influence the body's metabolic variables.
For their study, the researchers assessed the performance data of 580 Finnish males who were tested for military training. The test included stationary biking, weight lifting, blood testing, a general health screening and the completion of a lifestyle questionnaire. Based on the results, the subjects were split into two groups—one for aerobic fitness and one for muscular strength—and then ranked from strongest to weakest.
Finally, the researchers measured the ranked subjects' blood data for metabolites, or the molecular chemicals that are the reactants, intermediates or byproducts of enzyme-mediated biochemical reactions.
The subjects at the top of the aerobic fitness group exhibited the best metabolic profiles with healthy levels of proteins, good cholesterol, proteins and fatty acids. Interestingly, even the fittest subjects in the muscular strength group did not exhibit metabolic profiles that were as ideal as those at the top of the aerobic group, according to the study.
Additionally, the least-fit subjects in both groups exhibited inconsistent metabolites with their molecules varying by type, volume and ratio.
In short, cardio workouts such as running, biking or swimming may lead to the greatest metabolic benefits.
The study states: "This study provides data on the association of high aerobic fitness with underlying oxidative lipid metabolism associated with a reduction in cardiometabolic risk. High maximal muscular strength is not similarly associated with these benefits."
Other recent fitness studies have found that physical activity can improve brain function in young adults, and that seniors can effectively build muscle regardless of their past experience or lack thereof.