Rate-limiting Amino Acids in Endurance-trained Athlete (EA)

Application of Indicator Amino Acid Oxidation Method to Investigate the Rate-limiting Amino Acids in Endurance Trained Athlete

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.

Study Overview

• Status: Completed
• Conditions: Healthy; Increased Metabolic Requirement
• Intervention / Treatment: Dietary supplement: Base protein; Dietary supplement: Sufficient protein; Dietary supplement: Branched chain amino acids; Dietary supplement: Essential amino acids; Dietary supplement: Non essential amino acids

• Study Type: Interventional
• Enrollment (Actual): 5
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

Description

Gender: Male

Age limit: Minimum age 18 years - Maximum age 35 years

Accepts Healthy Volunteers : yes

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Base protein; 0.8 g/kg/d of protein provided as crystalline amino acid made after egg protein.	Dietary supplement: Base protein; 0.8 g/kg/d of protein provided as crystalline amino acid modeled after egg protein
Experimental: Sufficient protein; 1.75 g/kg/d protein provided as crystalline amino acid made after egg protein.	Dietary supplement: Sufficient protein; 1.75 g/kg/d protein provided as crystalline amino acid modeled after egg protein.
Experimental: Base + BCAA; Base protein intake + Branched chain amino acids	Dietary supplement: Base protein; 0.8 g/kg/d of protein provided as crystalline amino acid modeled after egg protein; Dietary supplement: Branched chain amino acids; Branched chain amino acids modeled after egg protein.
Experimental: Base + EAA; Base protein intake + essential amino acids.	Dietary supplement: Base protein; 0.8 g/kg/d of protein provided as crystalline amino acid modeled after egg protein; Dietary supplement: Essential amino acids; Essential amino acids modeled after egg protein.
Experimental: Base + NEAA; Base protein intake + non essential amino acids	Dietary supplement: Base protein; 0.8 g/kg/d of protein provided as crystalline amino acid modeled after egg protein; Dietary supplement: Non essential amino acids; Non essential amino acids modeled after egg protein.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
13CO2 (carbon dioxide) excretion rate (μmol/kg/h)	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.	At 8 hours after the end of exercise

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
[13C]phenylalanine oxidation rate (μmol/kg/h)	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.	at 8 hours after the end of exercise

Collaborators and Investigators

• Sponsor: University of Toronto

Publications and helpful links

General Publications

• Kato H, Suzuki K, Bannai M, Moore DR. Branched-Chain Amino Acids Are the Primary Limiting Amino Acids in the Diets of Endurance-Trained Men after a Bout of Prolonged Exercise. J Nutr. 2018 Jun 1;148(6):925-931. doi: 10.1093/jn/nxy048. Erratum In: J Nutr. 2018 Oct 1;148(10):1698.

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2015
• Primary Completion (Actual): June 1, 2017
• Study Completion (Actual): December 1, 2017

Study Registration Dates

• First Submitted: December 7, 2015
• First Submitted That Met QC Criteria: December 8, 2015
• First Posted (Estimate): December 11, 2015

Study Record Updates

• Last Update Posted (Actual): April 1, 2019
• Last Update Submitted That Met QC Criteria: March 28, 2019
• Last Verified: March 1, 2019

More Information

Terms related to this study

• Other Study ID Numbers: IAAO-EA