Effect of Post-exercise Nutrition on Glycemia in Women (PEN)

The purpose of this study is to assess whether post-exercise Greek yogurt following a single session of aerobic exercise improves metabolic and musculoskeletal health in women with overweight/obesity.

Following the acquisition of informed consent, eligibility to participate in the study will be determined using questionnaires. Participants will undergo baseline testing at our laboratory at the University of Toronto to determine cardiorespiratory fitness, body composition and undergo exercise familiarization. Eligible participants will be assigned, in a random order, to two metabolic trials approximately 4 weeks apart that involve 4 days of controlled diet and exercise. Each trial takes place over 4 days, but participants are not required to come to the laboratory on all days. The two trials involve: 1) Exercise + Greek Yogurt (GY) 2) Exercise + a carbohydrate-based study supplement (SS). During the 4 day trials, participants consume controlled diets and the study supplements (GY and SS). On 1 of these days participants will perform exercise in our lab followed by the consumption of GY or SS. Various outcomes will be measured throughout the trial, including glycemic control (via continuous glucose monitoring), fat oxidation, appetite and health outcomes in blood samples. Throughout the duration of the study, participants will be asked to maintain their habitual diet and physical activity patterns, and maintain their current body weight.

Participants will consume a carbohydrate-based study supplement following a single session of exercise

Following 2 days of controlled diet, participants will consume greek yogurt following high-intensity interval exercise

Following 2 days of controlled diet, participants will consume a carbohydrate-based study supplement following high-intensity interval exercise

Following 2 days of controlled diet, participants will perform high-intensity interval exercise following an overnight fast

Inclusion Criteria: 18-45 yrs BMI ≥27 kg/m2 Elevated waist circumference (≥88 cm) ≤2 structured exercise sessions/week Weight stable (within ± 2kg for at least 6 months) Experiencing regular natural menstrual cycles Non-smoker Exclusion Criteria: Allergy to dairy foods Diagnosed lactose intolerance or an aversion to foods provided during the study (e.g., post-exercise snacks) Previous history of cardiovascular or metabolic disease The use of medication for managing blood glucose or lipid metabolism Current use of oral contraceptives or use within the last 3 months Irregular menstrual cycles (<21 days or >35 days) Pregnant or lactating Recreational tobacco or cannabis use Inability to perform the study exercise protocols Actively engaging in a low-carbohydrate diet (e.g., ketogenic, Atkins).