How energy availability affects elite triathletes
Official title: Energy Availability in Elite Triathletes: Impact on Performance and Injury Risk
Run by Bispebjerg Hospital · NCT07232628 · Data updated 2026-11-12
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.
Quick facts
| Study type | Observational |
|---|---|
| Ages | 18 Years and up |
| Sex | All |
| Enrollment | 40 (estimated) |
| Sponsor | Bispebjerg Hospital Academic / other |
| Locations | 1 site (Copenhagen) |
| Status | Recruiting |
| Started | October 1, 2025 |
| Main results expected | November 30, 2027 |
| Study ends | June 2028 |
| Registry record updated | November 18, 2025 |
| Trial ID | NCT07232628 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Healthy men and women aged 18 or older who are elite or sub-elite triathletes training at least 15 hours per week are ideal candidates.
✕Probably not a fit
Recreational athletes training less than 15 hours per week, people with current injuries or illnesses that would be worsened by participation, smokers, or those using prohibited substances are unlikely to benefit or be eligible.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This two-season prospective cohort will follow 40 elite and sub-elite triathletes with five comprehensive test days spread across off-season, pre-season, and in-season periods. Assessments include blood sampling (with triiodothyronine/T3 as the primary outcome), DXA and MRI for bone and muscle, VO2max and performance testing, muscle strength and stiffness measures, dietary records, and wearable training data. Energy availability will be estimated using validated sex-specific questionnaires (LEAF-Q/LEAM-Q), MyFood24 dietary logs, and training load from wearable devices while participants continue their usual training and diet. The goal is to identify biomarkers and temporal patterns that connect low energy availability to performance changes, metabolic effects, and injury incidence.
Why it matters
Potential benefit: If successful, this could provide early biomarkers to detect low energy availability and help prevent performance decline and injury in endurance athletes.
How similar studies have gone: Previous observational work has linked low energy availability to hormonal changes, bone loss, and performance deficits, but longitudinal multi-season data specifically in elite triathletes is limited.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * Age ≥18 years * Healthy individuals * Training ≥15 hours/week in triathlon Exclusion Criteria: * Smokers * Use of prohibited substances (WADA list) without medical justification * Existing injuries or illnesses that could worsen due to participation
Where it's running
-
Institute of Sports Medicine Copenhagen, Bispebjerg Hospital
Copenhagen, Denmark Recruiting
Study contacts
- Study coordinator: Jakob Agergaard, Ph.D.
- Email: jakob.agergaard@regionh.dk
- Phone: +45 38 63 58 73
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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.