Novel Role of Exercise Timing in Obesity

The main objective of this research project is to assess the impact of the timing of exercise on sensory perception, more specifically on taste and smell. Also, the investigators want to identify the optimal exercise timing scenario that maximizes the short-term anorexigenic effect of exercise (i.e. decrease in energy intake at the meal following the exercise session) in each group of teenagers. Hypothesis: exercise immediately before a meal (EX-\>MEAL) will be the most efficient scenario, and will show a larger impact on males individuals and people who suffer obesity. Subsequently, the investigators want to understand the impacts of exercise on lifestyle habits (i.e. sleep and sedentariness). For the realization of this research project, the investigators plan to recruit approximately 144 participants, boys and girls with normal weight/obesity, aged 12 to 17 years. Of these participants, half will be male. There are two different exercise timings (i.e. performed at 9:30 am and 11:00 am using a treadmill to test the maximal aerobic capacity) and one sedentary control condition. Participants will take part in 3 experimental visits in a random order (\~5 hours/visit at LAPS-UdeM + 24h of real-life monitoring). Appetite sensations, energy intake (i.e. total and macronutrient), activity monitoring using actigraphy, hormonal (i.e. anorexigenic and orexigenic) and chemosensory (i.e. cortical response to taste and smell stimulations) response will be monitored in the laboratory and/or remotely. This project will measure acute response in laboratory and real-life settings.