A Finnish study indicates that many serum metabolites known to be associated with reduced cardio-metabolic risk are related to aerobic fitness. The bad news is that there are fewer beneficial associations with maximal muscular strength.
Jyväskylä/Finland — Epidemiological data show that high aerobic fitness predicts low risk of type 2 diabetes, coronary heart disease, and death. However, the associations were less clear for maximal muscular strength, says Professor Urho Kujala from the Faculty of Sport and Health Sciences at the University of Jyväskylä, Finland. Aside from other factors, the properties of skeletal muscle are suggested to contribute to aerobic fitness and muscular strength as well.
How aerobic fitness and muscular strength are associated with serum metabolome (metabolites produced during metabolism) were investigated. Participants (mean age 26 years) represented individuals with low vs. high aerobic fitness and low vs. high muscular strength. The examinations included a questionnaire, body composition measurement, maximal cycle ergometer test (aerobic fitness), maximal strength test for lower extremities (muscular strength), and fasting serum samples for nuclear magnetic resonance-based metabolomics analysis (66 metabolites were included for analysis).
Forty-eight of the 66 studied metabolite levels differed between the high vs. low aerobic fitness groups, and among the 580 men, aerobic fitness accounted for more than 5 % of the variation of 25 metabolites after adjustment for age, education, smoking, use of alcohol, and dietary factors. Fewer and smaller differences in the metabolite levels were seen according to muscular strength. Aerobic fitness was associated with low VLDL and high large HDL particle concentrations, low ApoB/ApoA1 ratio, low triglycerides, high unsaturation degree of fatty acids, and with low isoleucine, leucine, phenylalanine, glycerol, and glycoprotein concentrations.
This study contributes mechanistic understanding of how aerobic fitness and muscular strength are associated with risk factors for cardio-metabolic diseases. Genetic factors may explain some of the associations.
Many strength training modalities can not only improve maximal muscle strength, but also enhance aerobic fitness and functional capacity. However, in order to improve cardio-metabolic health, endurance-type training seems better because maximal muscle strength was not strongly associated with beneficial serum metabolome cardio-metabolic risk-factor levels.
Reference: Kujala UM, Vaara JP, Kainulainen H, Vasankari T, Vaara E, Kyröläinen H. Associations of aerobic fitness and maximal muscular strength with metabolites in young men. JAMA Network Open. 2019;2(8):e198265. doi:101001/jamanetworkopen.2019.8265