How energy availability affects elite triathletes
Energy Availability in Elite Triathletes: Impact on Performance and Injury Risk
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 |
|---|---|
| Enrollment | 40 (estimated) |
| Ages | 18 Years and up |
| Sex | All |
| Sponsor | Bispebjerg Hospital Academic / other |
| Locations | 1 site (Copenhagen) |
| Trial ID | NCT07232628 on ClinicalTrials.gov |
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.
Who should consider this trial
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.
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.
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 performed: 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.
Eligibility criteria
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 this trial is running
Copenhagen
- 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
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.