TY - JOUR T1 - Metabolic Flexibility Following High-Intensity Interval Exercise in Active Females: Effect of Feeding State AU - Ebrahimi, Maryam PY - 2025 DA - August Y2 - 2025 DO - 10.54141/psbd.1678172 JF - Pamukkale Journal of Sport Sciences JO - Pamukkale J Sport Sci PB - Pamukkale University WT - DergiPark SN - 1309-0356 SP - 387 EP - 397 VL - 16 IS - 2 LA - en AB - Metabolic flexibility is tightly regulated during exercise through the action of metabolites and metabolic enzymes. This randomized parallel-group study aimed to investigate how fed vs fasted state high-intensity interval exercise (HIIE) changes Glucose, lactate, pyruvate dehydrogenase kinase-4 (PDK-4), and carnitine palmitoyltransferase-1 (CPT-1) levels. 23 active females (20.09 ± 1.04 years of age) were selected from eligible volunteers and were randomly assigned into fed and 14-h fast groups. In each group, 6 participants randomly performed 1:4 HIIE (1 min all-out run, 4 min walk, for 20 minutes), and the other participants were seated. After a 5-minute cooldown, blood samples were collected from the brachial vein. Higher lactate levels were similar after HIIE in both feeding states. Fed-HIIE participants showed lower glucose levels, and fast-HIIE participants showed lower PDK-4 and CPT-1 levels than their control counterparts. It seems in the fasted 1:4 HIIE, glucose oxidation is the dominant energy production pathway. Lactate produced during exercise may be used as the precursor of gluconeogenesis in fasting. KW - CPT-1 KW - Glucose KW - HIIE KW - Lactate KW - PDK-4 CR - Adeva-Andany, M., López-Ojén, M., Funcasta-Calderón, R., Ameneiros-Rodríguez, E., Donapetry-García, C., Vila-Altesor, M., & Rodríguez-Seijas, J. (2014). Comprehensive review on lactate metabolism in human health. Mitochondrion, 17, 76-100. CR - Aird, T. P., Farquharson, A. J., Bermingham, K. 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