Understanding short-term low energy availability in endurance athletes
Official title: Unravelling Energy Issues Underpinning Low Energy Availability in High Performance Athletes
Run by Australian Catholic University · NCT07026175 · Data updated 2026-11-12
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
| Study type | Interventional |
|---|---|
| Ages | 18 Years to 45 Years |
| Sex | All |
| Enrollment | 20 (estimated) |
| Sponsor | Australian Catholic University Academic / other |
| Drugs / interventions | cart |
| Locations | 1 site (Fitzroy, Victoria) |
| Status | Recruiting |
| Started | September 4, 2025 |
| Main results expected | June 2027 |
| Study ends | June 2027 |
| Registry record updated | August 13, 2026 |
| Trial ID | NCT07026175 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a 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.
✕Probably 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.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
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.
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 gone: 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.
Who can join: the full rules
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 it's running
-
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
Similar studies
Other studies for the same condition or treatment. Recruiting studies are listed first.
-
How energy availability affects elite triathletes
This observational project will follow 40 elite and sub-elite triathletes to see if low energy availability links to changes in performance, injury risk, and health markers over two competitive seasons.
-
Preventing under-fueling in collegiate athletes with improved nutrition
This project will try routine nutrition screenings and sports-dietitian support to prevent low energy availability in Division III collegiate athletes at Case Western Reserve University.
How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.