AimTo describe lipid oxidation during physical activity (PA) in overweight and obese patients using a real-time capillary glycerol sensor and to propose a personalized strategy to optimize lipolysis. MethodsHealthy adult volunteers with a BMI >25 kg/m2 were recruited. All participants performed 27 sessions of 30-minute PA covering all possible combinations of exercises (low, moderate, high intensities) and pre-exercise meals (high-carbohydrate, high-fat, or fasting) with 3 replicates. Glycerol measurements were performed five times during each session: at T0, T20, T30, T45, and T60. The evolution of capillary glycerolemia during PA was modeled by a nonlinear mixed-effects model. We developed a personalized PA recommendation based on the first 2 glycerolemia measurements that indicates whether a change in activity type is preferable. ResultsThirteen patients were included in the study and 1232 capillary glycerolemia measurements were performed. Hyperglycemic and hyperlipidemic meals were associated with lower baseline glycerolemia (p<0.0001 for both) compared to fasting. In contrast, the type of meal was not significantly associated with PA-induced lipolysis (p=0.52 and p=0.76 for high-carbohydrate and hyperlipidemic meal respectively). Compared with exercises done at low and moderate intensities, high intensity exercises were associated with a higher PA-induced lipolysis (p=0.0002). Specific strength exercises were associated with a lower PA-induced lipolysis (p<0.0001). The 2 initial glycerolemia measurements appeared to be a pertinent criterion which help the personalization of PA programs for such individuals (c-index 0.67). ConclusionThe inter-individual lipolysis responses to PA and the availability of a real-time capillary blood glycerol sensor may enable the personalization of PA programs, thus promoting optimal lipolysis in subjects with overweight and obesity.