Non-invasive breath test to assess protein metabolism in young women

A 'Non-Invasive' Breath Test to Determine Anabolic Sensitivity in Females

Not applicable Interventional University of Toronto · NCT05422300

This study is testing a new breath test to see how well young women’s bodies use protein after eating and exercising, without needing any invasive procedures.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment10 (estimated)
Ages18 Years to 35 Years
SexFemale
SponsorUniversity of Toronto Academic / other
Locations1 site (Toronto, Ontario)
Trial IDNCT05422300 on ClinicalTrials.gov

What this trial studies

This study aims to validate a novel oral stable isotope tracer method to measure anabolic sensitivity in young adult females. By using an L-[13C]-leucine tracer, the researchers will assess how resistance exercise influences protein synthesis and retention in skeletal muscle. Participants will undergo testing after consuming a protein-rich meal, both at rest and following exercise, to determine the effectiveness of this non-invasive approach compared to traditional methods. The goal is to provide a more accessible way to evaluate protein metabolism without the need for invasive procedures.

Who should consider this trial

Good fit: Ideal candidates for this study are healthy females aged 18-35 who are recreationally active and have a BMI between 18.5 and 30.

Not a fit: Patients who are on oral contraceptives, have medical conditions affecting protein metabolism, or are unable to adhere to the study protocol may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a simpler and less invasive method for assessing protein metabolism, which may help optimize dietary and exercise recommendations for women.

How similar studies have performed: While traditional methods for assessing protein metabolism are well-established, this non-invasive approach is relatively novel and has not been extensively tested in similar studies.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Female sex
* 18-35 years of age
* BMI ≥18.5 kg/m2 and ≤ 30 kg/m2
* Eumenorrheic (self-reported menstruation for prior 3 consecutive months)
* Recreationally active; currently performing structured exercise (e.g. running, weightlifting, team-sport activity) at least once per week for ≥ 6 months before enrolment

Exclusion Criteria:

* Use of oral contraceptives
* Inability to perform physical activity as determined by the PAR-Q+
* Inability to adhere to protocol guidelines (e.g. alcohol, caffeine, habitual diet)
* Regular tobacco use
* Illicit drug use (e.g. growth hormone, testosterone, etc...)
* Diagnosed medical condition under the care of a physician (e.g. type 2 diabetes)
* Inability to abstain from supplements (e.g. protein, creatine, HMB, BCAA, phosphatidic acid, etc...) at least three weeks before the trial
* Individuals on any medications known to affect protein metabolism (e.g. corticosteroids, non-steroidal anti-inflammatories, and/or prescription-strength acne medications)

Where this trial is running

Toronto, Ontario

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Dietary ProteinFemale Protein MetabolismAnabolic SensitivityResistance ExerciseYoung Adult FemalesDietary Proteins/Administration & DosageSkeletal Muscle MetabolismHuman Adult Females
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.