Understanding short-term low energy availability in endurance athletes
Unravelling Energy Issues Underpinning Low Energy Availability in High Performance Athletes
NA · Australian Catholic University · NCT07026175
This trial will test how short-term, severe low energy availability—caused by either eating less or exercising more—affects sleeping metabolic rate and other body systems in weight-bearing endurance athletes aged 18–45.
Quick facts
| Phase | NA |
|---|---|
| Study type | Interventional |
| Enrollment | 20 (estimated) |
| Ages | 18 Years to 45 Years |
| Sex | All |
| Sponsor | Australian Catholic University (other) |
| Drugs / interventions | cart |
| Locations | 1 site (Fitzroy, Victoria) |
| Trial ID | NCT07026175 on ClinicalTrials.gov |
What this trial studies
Healthy weight-bearing endurance athletes aged 18–45 will complete a three-sequence crossover with three supervised 6-day trials separated by at least a 3-week washout. A control condition (≈40 kcal/kg fat-free mass/day with baseline exercise) is followed by two low energy availability (LEA) exposures delivered either via diet restriction (LEADIET) or increased exercise energy expenditure (LEAEX), with all meals provided and prescribed running/race walking. Baseline testing includes DXA body composition and BMD, aerobic capacity, resting metabolic rate, a LEA hormone panel, vitamin D, and REDs screening (REDs-CAT2) to individualize diet and exercise plans. Female participants begin trials in the follicular phase to standardize hormonal status, and supervised monitoring ensures safety and adherence throughout each 6-day exposure.
Who should consider this trial
Good fit: Well-trained, weight-bearing endurance athletes aged 18–45 who perform approximately 45 km/week of running or race walking, can complete the prescribed exercise, and can attend the Australian Catholic University site in Fitzroy for study visits are ideal candidates.
Not a fit: Individuals already identified as REDs-positive by the REDs Clinical Assessment Tool, those who are pregnant, recently on hormonal contraceptives, peri/menopausal, or unable to attend the Fitzroy site are unlikely to benefit from participation.
Why it matters
Potential benefit: If successful, findings could help coaches and clinicians design safer nutrition and training strategies to prevent REDs and protect athlete health and performance.
How similar studies have performed: Previous research has documented hormonal and metabolic changes with LEA, but directly comparing short-term, severe LEA induced by diet versus increased exercise in a controlled crossover design is relatively novel.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * 18-45 years old * Well trained weight-bearing athlete (tier 2-4 1) * Perform \~45km per week of weight-bearing endurance training, and able to undertake the prescribed exercise in each trial condition * Pass the ESSA pre-exercise screening tool and/or obtain GP clearance to exercise Exclusion Criteria: * Assessment of red status on the REDs Clinical Assessment Tool * Unable to attend ACU in Fitzroy, Victoria, for the 6 study visits for completion of the study protocol * Pregnancy * Use of hormonal contraceptive with the previous 3 months * Onset of peri/menopause
Where this trial is running
Fitzroy, Victoria
- Australian Catholic University — Fitzroy, Victoria, Australia (RECRUITING)
Study contacts
- Principal investigator: Louise M Burke, PhD — Australian Catholic University
- Study coordinator: Louise M Burke, PhD
- Email: louise.burke@acu.edu.au
- Phone: +61 4 22 635 869
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions: Relative Energy Deficiency in Sport, Endurance, Athlete, Sleeping Metabolic Rate, Problematic Low Energy Availability