Effect of Non-essential Amino Acids on Protein Requirements for Endurance Athletes

University of Toronto7 enrolled

Overview

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 its amino acid composition. Essential amino acids are believed to have main role on whole body protein metabolism. However, it remains to be determined what role non-essential amino acids (NEAA) may have in regulating protein metabolism and contributing to the increased protein requirements after endurance exercise. 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 assessing the effect of NEAA on protein requirements after endurance exercise. The objective of the current study is to investigate the importance of NEAA for endurance-trained male subjects.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Enrollment

Conditions

Increased Metabolic Requirement Healthy

Interventions

BASE egg proteinDIETARY_SUPPLEMENT

0.8 g/kg/d of protein provided as crystalline amino acid modeled after egg protein

BCAA-enriched egg proteinDIETARY_SUPPLEMENT

BCAA-enriched egg protein provided as crystalline amino acid.

small amount of essential amino acidsDIETARY_SUPPLEMENT

essential amino acids modeled after egg protein, provided as crystalline amino acid, which is equivalent to the amount of essential amino acid in BASE egg protein

large amount of essential amino acidsDIETARY_SUPPLEMENT

essential amino acids modeled after egg protein, provided as crystalline amino acid, which is equivalent to the amount of amino acid in BCAA-enriched egg protein

Eligibility

Sex: MALEMin age: 18 YearsMax age: 40 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * endurance-trained participants who regularly run more than 40 km/week * Participants who are categorized at least "very good" based on a study by Shvartz \& Reibold, in which VO2peak is used as an index. (i.e. the participants whose VO2peak is ≥57 ml/kg/min (18-24 y), ≥54 ml/kg/min (25-29 y), ≥52 ml/kg/min (30-34 y), ≥49 ml/kg/min (35-39 y) * Ability to complete the 16-km familiarization run in session 2 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

Outcomes

Primary Outcomes

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.

Time frame: at 8 hours after the end of exercise]

Secondary Outcomes

[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.

Time frame: at 8 hours after the end of exercise