Effect of a Physical Exercise Session Performed During a 24-34 Hour Fasting Period on Energy Metabolism and Cognitive Function in Healthy Adults

Inclusion Criteria: * 18-40 years old. * Body mass index: 18.5-30.0 Kg/m2. * Stable body weight (5kg range within the last 3 months) * Being able to consume all the food items provided as part of the study. * Not having change the time zone or have shifted sleeping hours equivalent to more than 3 hours on the previous 2 weeks. Exclusion Criteria: * Diagnosed with any chronic condition that, in the research team's opinion or based on the American College of Sports Medicine guidelines, could contraindicate the implementation of 34-hour fasting periods and/or high-intensity exercise. * Diagnosed with a chronic endocrine, digestive, rheumatic, neurological, cardiac, pulmonary, autoimmune, or infectious condition that affects energy metabolism. * Presenting any signs or symptoms of illness that, in the research team's opinion or based on the American College of Sports Medicine guidelines, could contraindicate the implementation of 34-hour fasting periods and/or high-intensity exercise. * Pregnant or breastfeeding. * Using medications or supplements that may alter energy metabolism. * Currently undergoing or having undergone any type of nutritional intervention or treatment in the past 3 months. * Engaging in more than 5 hours per week of habitual moderate-to-vigorous cycling. * Any other condition that, in the research team's opinion, discourages participation in the study.