Insulin Resistance Is Not Associated With Perceived Exertion or Cerebral Oxygenation During Exercise in Women

Insulin resistance (IR) may jeopardise cerebral oxygenation and increase perceived exertion during exercise. We investigated whether IR is independently associated with perceived exertion or cerebral oxygenation during exercise and whether perceived exertion is associated with cerebral oxygenation during exercise. 48 premenopausal apparently healthy women underwent a cardiopulmonary exercise test (CPET) in this retrospective cross-sectional study. We assessed IR with the homeostasis model assessment (HOMA-IR). In addition to basic CPET data, we quantified cardiac function (impedance cardiography) and prefrontal cerebral oxygenation (near-infrared spectroscopy [NIRS]) during CPET. We divided the subjects into women with HOMA-IR< 3.0 (HOMA_LOW) vs. women with HOMA-IR≥ 3.0 (HOMA_HIGH), and into women with lower RPE/MET (rating of perceived exertion/metabolic equivalent) slope (RPE/MET_LOW) vs. women with higher RPE/MET slope (RPE/MET_HIGH). RPE or NIRS responses to exercise did not differ between HOMA-IR groups. NIRS responses to exercise did not differ between RPE/MET groups. NIRS responses did not correlate with HOMA-IR or RPE/MET slope in all subjects. In multivariate regression analyses, a higher RPE/MET slope was predicted only by higher body mass index and weaker lung function. In conclusion, we found no associations between IR, cerebral oxygenation, and perceived exertion, whereas body mass index and lung function were independently associated with exercise-related perceived exertion.