Protein Requirements in Male and Female Endurance Athletes

NCT04855474 | Completed

• 1 other identifier: IAAO-ETFM
• Study Type: interventional
• Target: 16
• Locations: 1 country
• Sites: 1

Brief Summary

Protein is an essential macronutrient for post-exercise recovery through its ability to provide the amino acid building blocks that support increased rates of muscle and whole body protein synthesis. Despite the growing understanding of the importance of post-exercise protein in endurance athlete populations, the impact of sex and female menstrual cycle phase on protein metabolism is not fully understood. To date, no studies have examined protein requirements in female endurance trained athletes. The aim of the proposed study is to utilize the well-established IAAO method to determine protein requirements in endurance trained female and male athletes in a "real-world" and at-home setting.

Conditions

Increased Metabolic Requirement; Healthy

Outcome Measures

Primary Outcomes (1)

• Phenylalanine excretion

  13CO2 production in umol/kg/h

  8 hours

Secondary Outcomes (2)

• Phenylalanine Oxidation

  8 hours

• Phenylalanine net balance

  8 hours

Other Outcomes (2)

• Urinary 3-methylhistidine

  8 hours

• Protein requirement

  8 hours

Study Arms (3)

Low Protein

EXPERIMENTAL

0.2 g/kg/day of protein provided as crystalline amino acid made after egg protein.

Dietary Supplement: Amino Acid Intake

Moderate Protein

EXPERIMENTAL

1.2g/kg/day of protein provided as crystalline amino acid made after egg protein.

Dietary Supplement: Amino Acid Intake

High Protein

EXPERIMENTAL

2.0 g/kg/day of protein provided as crystalline amino acid made after egg protein.

Dietary Supplement: Amino Acid Intake

Interventions

Amino Acid Intake DIETARY_SUPPLEMENT

Participants will consume hourly (8 hours) isoenergetic, isonitrogenous beverages containing one of the three protein intakes (0.2g/kg/d, 1.2 g/kg/d, 2.0g/kg/d) assigned in a randomized order between the three metabolic trials. Drinks will be enriched with stable isotope \[13C\]phenylalanine. The use of stable isotope \[13C\]phenylalanine will allow for the determination of the fate of AA in the body (incorporation into body protein or oxidation) which can be used to determine protein (AA) requirements.

High Protein; Low Protein; Moderate Protein

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy endurance trained runners. Total weekly running distance of greater than 50km/week and perform endurance exercise for more than 5 hours/week.
• Age 18-35 years old
• Eumenorrheic over last 3 months (one cycle no longer than 42 days and no shorter than 20 days).
• Not using hormonal contraceptives (the pill, implants and injections, hormonal intrauterine devices (IUDs), vaginal ring, skin patch).
• Do not have polycystic ovarian syndrome (PCOS) or other conditions effecting ovarian hormone regularity.
• Not pregnant within the past year.
• Must meet the classification of 'superior' aerobic power for their respective age category based on the ACSM criteria; (women age 20-29 years VO2max \>50ml/kg/min and women age 30-35 years VO2max \>46ml/kg/min) (men age 20-29 years VO2max \>56ml/kg/min and men age 30-35 years VO2max \>54ml/kg/min).

You may not qualify if:

• Inability to meet health and physical activity guidelines according to the CSEP 'Get Active' Questionnaire (Appendix G).
• Inability to adhere to study protocol requirements relating to diet and exercise (i.e. alcohol and caffeine consumption, training/exercise prior to beginning a study testing day).
• Regular use of tobacco and/or other recreational drugs/banned substances (i.e. growth hormone, testosterone, marijuana).
• Self-reported intentional or unintentional weight loss (past 6 months) or plan to lose weight (\>5-10kg).
• Amenorrhea (self-reported) in the past 3 months.
• Fewer than 6 menstrual cycles per year.
• Answering yes to any questions asked within the COVID-19 screening questionnaire until 14 days of being symptom free and/or having a negative COVID-19 test

Sponsors & Collaborators

• University of Toronto: lead

Study Sites (1)

Goldring Centre for High Performance Sport

Toronto, Ontario, M5S2C9, Canada

Location

Related Publications (1)

• Williamson E, Fung HJW, Adams C, West DWD, Moore DR. Protein Requirements Are Increased in Endurance-Trained Athletes but Similar between Females and Males during Postexercise Recovery. Med Sci Sports Exerc. 2023 Oct 1;55(10):1866-1875. doi: 10.1249/MSS.0000000000003219. Epub 2023 May 19.

  PMID: 37710376 DERIVED

Study Officials

• Daniel Moore, Ph.D

  University of Toronto

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Model Details: Eight men and eight women will be provided three different amino acid intakes on three separate occasions (metabolic trials) over 8 hours following a 20km run. All protein intakes have an amino acid composition modelled off of the profile of egg protein.

Study Record Dates

• First Submitted: April 18, 2021
• First Posted: April 22, 2021
• Study Start: March 8, 2021
• Primary Completion: October 31, 2021
• Study Completion: December 30, 2022
• Last Updated: July 13, 2023

Record last verified: 2023-07

Data Sharing

• IPD Sharing: Will share

Locations

CA (1)