The effects of Montmorency tart cherry juice supplementation and FATMAX exercise on fat oxidation rates and cardio-metabolic markers in healthy humans

Montmorency tart cherries (Prunus cerasus L.) are rich in anthocyanins, compounds capable of augmenting fat oxidation and regulating metabolic dysfunction. The present study examined whether Montmorency tart cherry juice (MTCJ) supplementation could augment fat oxidation rates at rest and during FATMAX exercise, thus improve cardio-metabolic health. Eleven, healthy participants consumed MTCJ or placebo (PLA) twice daily, in a randomised, counterbalanced order for 20 days. Participants cycled at FATMAX for 1-h pre-, mid- (10 days) and post-supplementation whilst substrate oxidation rates were measured. Before exercise anthropometrics and resting metabolic rate were measured. Blood pressure, serum triglycerides, cholesterol, HDL, total antioxidant status (TAS) and glucose were measured immediately before and after exercise. No significant differences between conditions or interactions were observed for any functional and blood-based cardio-metabolic markers or fat oxidation during exercise or rest (P > 0.05). Pre-exercise TAS (P = 0.036) and HDL (P = 0.001) were significantly reduced from mid- to post-supplementation with MTCJ only. Twenty days’ MTCJ supplementation had no effect on fat oxidation; therefore, it is unnecessary for individuals in this participant cohort to consume MTCJ with exercise to improve cardio-metabolic biomarkers.