Unravelling Energy Issues Underpinning Low Energy Availability in High Performance Athletes
1 other identifier
interventional
20
1 country
1
Brief Summary
The goal of this clinical trial is to understand how the body responds to short-term, severe low energy availability (LEA) in healthy, weight-bearing endurance athletes aged 18-45 years old. LEA describes a mismatch between an individual's dietary energy intake and the energy cost of their commitments for training and competition. The main questions this trial aims to answer are:
- Prescribed diet (all food provided)
- Prescribed running and/or cycling exercise
- Two visits to ACU Fitzroy campus for blood tests and exercise testing
- 50 hour stay (two nights and two days) in the ACU metabolic chamber
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at below P25 for not_applicable
Started Jun 2025
Typical duration for not_applicable
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
Click on a node to explore related trials.
Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
May 28, 2025
CompletedStudy Start
First participant enrolled
June 1, 2025
CompletedFirst Posted
Study publicly available on registry
June 18, 2025
CompletedPrimary Completion
Last participant's last visit for primary outcome
June 1, 2027
ExpectedStudy Completion
Last participant's last visit for all outcomes
June 1, 2027
June 18, 2025
June 1, 2025
2 years
May 28, 2025
June 10, 2025
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Sleeping metabolic rate between trials, measured using a human metabolic chamber on night 5 of each trial condition.
The primary outcome is the within-participant and sex-based difference in Sleeping Metabolic Rate (SMR) across the three trial conditions. Analyses will also compare differences in SMR responses between sexes.
Night 5 of each trial condition from enrolment to the end of the third trial period.
Other Outcomes (21)
Fasting values of metabolic and reproductive hormones between trials.
Day 1 of each trial condition from enrollment to Day 5 of the third trial period.
Overnight pulsatility of luteinising hormone between trials.
Night 4 of each trial condition from enrolment to Day 5 of the third trial period.
Overnight pulsatility of growth hormone between trials.
Night 4 of each trial condition from enrolment to Day 5 of the third trial period.
- +18 more other outcomes
Study Arms (3)
Control Trial
NO INTERVENTIONA 6-day control trial. All participants will commence with this trial involving an energy availability of 40 kcal/kg fat-free mass (FFM). Energy intake will be 55 kcal/kg FFM/d and exercise energy expenditure will be 15 kcal/kg FFM/d. This will be followed by a minimum 3-week washout period where the participant will be advised to return to their routine diet and exercise.
Low Energy Availability - Diet
EXPERIMENTALA 6-day severe low energy availability (LEA, 15kcal/kg FFM/d) trial, achieved by superimposing restricted energy intake on the HEA trial. Energy intake will be 30 kcal/kg FFM/d and exercise energy expenditure will be 15 kcal/kg FFM/d. This will be followed by a minimum 3-week washout period where the participant will be advised to return to their routine diet and exercise.
Low Energy Availability - Exercise
EXPERIMENTALA 6-day severe low energy availability (LEA, 15kcal/kg FFM/d) trial, achieved by superimposing increased exercise energy expenditure on the HEA trial. Energy intake will be 45 kcal/kg FFM/d and exercise energy expenditure will be 30 kcal/kg FFM/d. This will be followed by a minimum 3-week washout period where the participant will be advised to return to their routine diet and exercise.
Interventions
6-days of severe low energy availability (LEA, 15kcal/kg FFM/d), achieved by superimposing restricted energy intake on the control trial.
6-days of severe low energy availability (LEA, 15kcal/kg FFM/d), achieved by superimposing increased exercise energy expenditure on the control trial.
Eligibility Criteria
You may qualify if:
- 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
You may not qualify if:
- 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
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Australian Catholic Universitylead
- Wu Tsai Human Performance Alliancecollaborator
Study Sites (1)
Australian Catholic University
Fitzroy, Victoria, 3065, Australia
Related Publications (3)
Burke LM, Ackerman KE, Heikura IA, Hackney AC, Stellingwerff T. Mapping the complexities of Relative Energy Deficiency in Sport (REDs): development of a physiological model by a subgroup of the International Olympic Committee (IOC) Consensus on REDs. Br J Sports Med. 2023 Sep;57(17):1098-1108. doi: 10.1136/bjsports-2023-107335.
PMID: 37752007BACKGROUNDMountjoy M, Ackerman KE, Bailey DM, Burke LM, Constantini N, Hackney AC, Heikura IA, Melin A, Pensgaard AM, Stellingwerff T, Sundgot-Borgen JK, Torstveit MK, Jacobsen AU, Verhagen E, Budgett R, Engebretsen L, Erdener U. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med. 2023 Sep;57(17):1073-1097. doi: 10.1136/bjsports-2023-106994.
PMID: 37752011BACKGROUNDLoucks AB, Kiens B, Wright HH. Energy availability in athletes. J Sports Sci. 2011;29 Suppl 1:S7-15. doi: 10.1080/02640414.2011.588958. Epub 2011 Jul 28.
PMID: 21793767BACKGROUND
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Louise M Burke, PhD
Australian Catholic University
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- NONE
- Purpose
- BASIC SCIENCE
- Intervention Model
- CROSSOVER
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
May 28, 2025
First Posted
June 18, 2025
Study Start
June 1, 2025
Primary Completion (Estimated)
June 1, 2027
Study Completion (Estimated)
June 1, 2027
Last Updated
June 18, 2025
Record last verified: 2025-06
Data Sharing
- IPD Sharing
- Will share
- Time Frame
- For a period of 36 months from publication of the primary outcome.
The data that support the findings of this study will be available from the corresponding author for a period of 36 months from publication, upon reasonable request for academic use. The data will not be made publicly available, as it contains information that could compromise research participant consent.