Rate-limiting Amino Acids in Endurance-trained Athlete

Not Applicable

Completed

• Conditions: Increased Metabolic Requirement; Healthy
• Interventions: Dietary Supplement: Base protein; Dietary Supplement: Sufficient protein; Dietary Supplement: Branched chain amino acids; Dietary Supplement: Non essential amino acids; Dietary Supplement: Essential amino acids

• Registration Number: NCT02628249
• Lead Sponsor: University of Toronto

Brief Summary

Protein requirements in individuals who participate in endurance-based exercise training have been suggested to be greater than the current recommended dietary allowance (RDA).

The biological value of protein depends on the amino acid composition. As liebig's law of the minimum, the protein synthesis is limited due to the lack of single rate limiting amino acid. In this case, the first rate limiting amino acid determines protein intakes to maximize the protein synthesis. Adding a small amount of rate-limiting amino acid to the diet improves the biological value of its protein diet.

The indicator amino acid oxidation (IAAO) method has clarified the individual amino acid requirement in children, normal healthy adult and clinical populations. however, the IAAO method has never been utilized for determining the first rate limiting amino acid.

Therefore, the purpose of this study is to address of IAAO method to be applied for determining the rate-limiting amino acid in endurance athlete.

Detailed Description

Not available

Study Timeline

• Study Start: 2015-09
• Study First Submitted: 2015-12-07
• Study First Submitted QC: 2015-12-08
• Study First Posted: 2015-12-11
• Primary Completion: 2017-06
• Study Completion: 2017-12
• Status Verified: 2019-03
• Last Update Submitted: 2019-03-28
• Last Update Posted: 2019-04-01

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 5

Inclusion Criteria

• Endurance-trained participants who regularly more than 40 km/week
• Ability to perform the exercise stimulus (20 km run) on metabolic trial.

Exclusion Criteria

• Inability to meet health and physical activity guidelines according to the physical activity readiness questionnaire (PAR-Q+)
• Inability to adhere to any of the protocol guidelines (i.e. alcohol, caffeine consumption)
• Regular tobacco use
• Illicit drug use

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Base + NEAA	Base protein	Base protein intake + non essential amino acids
Base protein	Base protein	0.8 g/kg/d of protein provided as crystalline amino acid made after egg protein.
Base + BCAA	Base protein	Base protein intake + Branched chain amino acids
Base + BCAA	Branched chain amino acids	Base protein intake + Branched chain amino acids
Sufficient protein	Sufficient protein	1.75 g/kg/d protein provided as crystalline amino acid made after egg protein.
Base + NEAA	Non essential amino acids	Base protein intake + non essential amino acids
Base + EAA	Base protein	Base protein intake + essential amino acids.
Base + EAA	Essential amino acids	Base protein intake + essential amino acids.

Primary Outcome Measures

Name	Time	Method
13CO2 (carbon dioxide) excretion rate (μmol/kg/h)	At 8 hours after the end of exercise	8 hours after exercise followed by ingesting 13C-labelled phenylalanine and one of 5 different amount of amino acids intake, 13CO2 excretion rate is determined by multiplying the enrichment of 13CO2 in breath measured by Mass spectrometry and CO2 production rate measured by metabolic cart.

Secondary Outcome Measures

Name	Time	Method
[13C]phenylalanine oxidation rate (μmol/kg/h)	at 8 hours after the end of exercise	8 hours after exercise followed by ingesting 13C-labelled phenylalanine and one of 5 different amount of amino acids intake, 13CO2 excretion rate is determined dividing 13CO2 excretion rate by urinary enrichment of 13C-phenylalanine in breath measured by Mass spectrometry, and CO2 production rate measured by metabolic cart.