During the NVDO meeting, Maaike Bergman presented her work on the assessment of metabolic flexibility upon insulin stimulation and incremental submaximal exercise.
Metabolic flexibility is defined as the adaptability of substrate oxidation to substrate availability, which is commonly measured as the change in respiratory exchange ratio. In obese, metabolically compromised subjects, metabolic flexibility is disrupted, expressed by a blunted change from fat to glucose oxidation upon insulin stimulation. As exercise of progressive intensity also requires a gradual switch from fat to glucose oxidation but is not dependent on insulin for glucose uptake, we aimed to investigate if metabolic flexibility upon insulin stimulation is similar to metabolic flexibility assessed during progressive exercise, specifically in the switch from 30% and 70% of the maximal power output.
Although metabolic flexibility measured upon insulin stimulation quantitatively matches metabolic flexibility assessed during exercise of progressive intensity in obese elderly, there was no association between these two measures of metabolic flexibility in this population.