2.3.5. Exercise Protocol
Exercise protocols were completed on a treadmill at a speed and grade designed to bring the estimated heart rate reserve (HRR) of each participant to 70%. This type of exercise is considered intense [The following formula was used to estimate maximal HR [A strap-on heart rate monitor (Garmin, Olathe, KS, USA) was fitted to the participant, and they were then instructed to sit for 5 min to establish their resting HR (HRrest). Once HR calculations were complete, subjects began the exercise. On the treadmill, the speed and grade were adjusted and set to cause the participant to meet their target HR within 5 min after beginning exercise. Once set, the speed and grade were not adjusted. Participants were expected to maintain this intensity for the entire duration of the exercise; however, if a participant was unable to maintain the exercise intensity, they were permitted a 60-s break before resuming.The exercise duration was individualized in order for each participant to expend approximately the same number of calories as they consumed in the standardized meal. The energy expenditure calculation was based on the ACSM metabolic equation, which converts oxygen to calories by multiplying liters of oxygen by 5.Standard ACSM metabolic equation:Equations to estimate exercise duration:E = energy from a meal (kilocalories);kg = participant’s weight (kilograms);S = treadmill speed (meters per minute);G = grade of the treadmill (percent incline);min = time on the treadmill (minutes).All calculations were performed in a protected spreadsheet using the above preset equations to ensure accuracy. Energy expenditure was verified using indirect calorimetry throughout the entire duration of the exercise (COSMED, Rome, Italy).