Study of Short-Term Severe Low Energy Availability Effects on Metabolism and Body Systems in Endurance Athletes Aged 18-45

What this Trial Is About

Researchers are studying how the body of healthy, weight-bearing endurance athletes aged 18 to 45 responds to short-term, severe low energy availability LEA. LEA occurs when there is a mismatch between dietary energy intake and the energy used for training and competition. The study aims to understand the effects of LEA on sleeping metabolic rate and other body systems affected by Relative Energy Deficiency in Sport REDs. Researchers will compare a control trial with two LEA trials achieved through diet restriction and increased exercise to identify differences in the bodys response. Participants will complete three separate 6-day trials with at least 3 weeks between them. The first trial is a control with normal energy availability, followed by two severe LEA trials one with reduced dietary intake and one with increased exercise energy expenditure. Each trial involves prescribed diets managed by sports dietitians, specific running and cycling exercises, and stays at the Australian Catholic University ACU Fitzroy campus for testing. During the last two days of each trial, participants will stay in a metabolic chamber for detailed monitoring. Throughout the study, participants will undergo various tests including body composition scans, aerobic capacity, hormone panels, cognitive tests, and continuous monitoring of sleep, heart rate, and energy expenditure using wearable devices. Blood samples, urine collections, exercise tests, and questionnaires will help assess metabolic, hormonal, immune, and bone health. Researchers will measure sleeping metabolic rate as the primary outcome and monitor participants closely during each trial and washout periods. The total participation involves multiple visits and data collection points over several months.

Unravelling Energy Issues Underpinning Low Energy Availability in High Performance Athletes