Iron and Muscular Damage: FEmale Metabolism and Menstrual Cycle During Exercise

Exercise Induced Iron-deficiency, Exercise Induced Muscle Damage, Inflammation, Iron-deficiency, Iron Metabolism Disorders, Regulation of Sex Hormones on Hepcidin, Regulation of Sex Hormones on Muscle Damage

Hepcidin, Iron deficiency, Menstrual cycle, Muscle damage, Creatine kinase, Female, Exercise, Estrogen, Progesterone, Oral contraceptives, Postmenopausal women

This project is an observational controlled randomized counterbalance study. One hundred and three physically active and healthy women were selected to participate in the IronFEMME Study, of which 57 were eumenorrheic, 30 were oral contraceptive users (OCP) and 16 were postmenopausal women. The project consisted on two sections carrying out at the same time: Iron metabolism (Study I) and Muscle damage (Study II). For the study I, the exercise protocol consisted on an interval running test (8 bouts of 3 min at 85% of the maximal aerobic speed), whereas the study II protocol was based on an eccentric-based resistance exercise protocol (10 sets of 10 repetitions of plate-loaded barbell parallel back squats at 60% of their 1RM with 2 min of rest between sets). In both studies, eumenorrheic participants were evaluated at three specific moments of the menstrual cycle: Early-follicular phase, late-follicular phase and mid-luteal phase; OCP performed the trial at two moments: Withdrawal phase and active pill phase. Lastly, postmenopausal women were tested only once, since their hormonal status does not fluctuate. The three-step method was used to verify the menstrual cycle phase: calendar counting, blood analyses confirmation and urine-based ovulation kits. Blood samples were obtained to measure sexual hormones (e.g., 17β-Estradiol, Progesterone), iron metabolism parameters (e.g., Hepcidin, Iron, Ferritin, Transferrin) and muscle damage related markers (e.g., Creatine Kinase, Myoglobin, Lactate Dehydrogenase).

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