Protein Requirements Amongst Male Masters-Level Athletes Following a Cycling Exercise Bout as Determined by the Indicator Amino Acid Oxidation Technique

February 5, 2026 updated by: Tyler Churchward-Venne, McGill University

Masters level cyclists are a population above the age of 35 years who frequently participate in prolonged as well as heavy-volume training. Like most endurance-trained athletes, a greater recommended dietary allowance (RDA) for protein of 1.2-1.4 g/kg/bw is suggested.

Dietary protein intake is vital for maximizing the benefits of training and ensuring optimal recovery. Dietary recommendations traditionally have been determined through nitrogen balance techniques, however, recent research indicates how this method is potentially underestimating protein requirements. Therefore, there is a need to reassess current dietary recommendations in order to meet the demands of physical activity for highly active populations.

Recent efforts to understand protein requirements during rest and following exercise have been completed using the indicator amino acid technique (IAAO). This non-invasive method is reported to provide a robust measure of protein requirements. However, there is limited work in older (≥60 years) active populations.

The purpose of this study is to measure the protein requirements in master cyclists, following an endurance training session, using the non-invasive IAAO technique.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

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Intervention / Treatment

Intervention / Treatment

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Study Type

Study Type

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Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
8

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

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Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Canada
    • Quebec
      • Montreal, Quebec, Canada, H3A 0G4
        • Recruiting
        • McGill University
        • Contact:
        • Principal Investigator:
          • Tyler Churchward-Venne, PhD
        • Sub-Investigator:
          • Damian Papadopoulos, BSc
        • Contact:

Participation Criteria

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Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • 18.5< BMI <35 kg/m^2
  • Overtly healthy masters level cyclists ≥65 years
  • Masters level cyclist training (>4 days per week; ~100 km per week)
  • Body mass stable over previous 6-months
  • Availability for multiple metabolic trials (~7 trials)
  • Ability to travel to and from laboratory facility

Exclusion Criteria:

  • Recent history of weight loss or weight gain (>5% body weight)
  • Uncontrolled hypertension
  • ≥2 chronic diseases (e.g. diabetes, osteoporosis, dyslipidemia)
  • Acute illness that could affect protein metabolism (HIV, renal dysfunction, influenza)
  • Currently using anti-inflammatory medications
  • Inability to adhere to study protocol (i.e., alcohol, caffeine, dietary restrictions)
  • Regular tobacco user
  • Illicit drug use
  • Habitually ingesting ≥3 g/kg/bw

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Masters Level Cyclists
Participants are to be randomly assigned varying levels of amino acid intakes ranging between 0.2 to 2.8 g/kg/d
Dietary supplement: Amino Acid Intake
Amino acid intakes will vary between 0.2 to 2.8 g/kg/d

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
13CO2 Excretion
Time Frame: 7-weeks
Measured by continuous-flow isotope ratio mass spectrometry
7-weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
L[13C]phenylalanine Oxidation
Time Frame: 7-weeks
Measured by gas chromatography-mass spectrometry
7-weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
McGill University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 21, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 22, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 22, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
May 28, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 9, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 5, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • A06-M25-23A

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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