The Impact of Protein Intake on Protein Metabolism During Intensified Training

Not Applicable

Completed

• Conditions: Healthy
• Interventions: Dietary Supplement: Normal; Dietary Supplement: Moderate; Dietary Supplement: High; Other: Controlled-diet

• Registration Number: NCT02801344
• 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).

Our recent study using the minimally invasive indicator amino acid oxidation (IAAO) technique have suggested that protein requirements in young men are at least 30% higher than the recommended protein intake.

The present study will investigate the impact of protein sufficiency on protein metabolism and performance during intensified training periods as a means to further our understanding of the nutritional requirements for the endurance athlete.

Detailed Description

Not available

Study Timeline

• Study Start: 2016-05
• Study First Submitted: 2016-05-25
• Study First Submitted QC: 2016-06-10
• Study First Posted: 2016-06-15
• Primary Completion: 2017-09
• Study Completion: 2018-02
• Status Verified: 2019-03
• Last Update Submitted: 2019-03-28
• Last Update Posted: 2019-03-29

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 12

Inclusion Criteria

• Healthy, male, endurance-trained participants who have run regularly more than 45 km or 4.5 hours/week
• Participants who are categorized at least "very good" based on a study by Shvartz & Reibold [40], in which peak rate of oxygen consumption(VO2 Peak) 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), ≥47 ml/kg/min (40-44 y), ≥44 ml/kg/min (45-50 y) according to his age,
• Participants who can cover 10 km in less than 60 min after the VO2peak test and 5 km Time trial on session 2.
• Participants will be 18-50 years old.
• Participants are willing to abide by the compliance rules of this study

Exclusion Criteria

• Inability to meet health and physical activity guidelines according to the The Physical Activity Readiness Questionnaire for everyone.
• Female
• Inability to adhere to any of the compliance rules judged by principal investigator or medical doctor
• Regular tobacco use
• Illicit drug use (e.g. growth hormone, testosterone, etc.)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Normal protein intake	Normal	participants will receive the controlled-diet containing 0.8 g protein /kg/day and the test drink containing 0.14 g protein/kg/d.
Moderate protein intake	Moderate	participants will receive the controlled-diet containing 1.20 g protein /kg/day and the test drink containing 0.40 g protein/kg/d.
Moderate protein intake	Controlled-diet	participants will receive the controlled-diet containing 1.20 g protein /kg/day and the test drink containing 0.40 g protein/kg/d.
High protein intake	Controlled-diet	participants will receive the controlled-diet containing 1.83 g protein /kg/day and the test drink containing 1.03 g protein/kg/d.
Normal protein intake	Controlled-diet	participants will receive the controlled-diet containing 0.8 g protein /kg/day and the test drink containing 0.14 g protein/kg/d.
High protein intake	High	participants will receive the controlled-diet containing 1.83 g protein /kg/day and the test drink containing 1.03 g protein/kg/d.

Primary Outcome Measures

Name	Time	Method
Change in 24h whole body protein balance	Difference between day 1 and day 4 whole body protein balance	Protein balance (mg/kg/d; protein synthesis - protein breakdown) will be measured using \[15N\]Glycine method on day 1 and day 4 to determine the change over the intensified training period to compare between protein levels

Secondary Outcome Measures

Name	Time	Method
Change from baseline physical performance (5 km time trial) 5days after the beginning of training	5days after the beginning of training	Before and after 4 days of intensified training period, Duration (seconds) for completing 5-km running on treadmill will be measured.
change from baseline Physical performance (muscle strength) 5days after the beginning of training	5days after the beginning of training	Maximal strength will be assessed by a maximal isometric voluntary contraction (MVC), which will be tested for the knee-extensors using a custom-made knee-extension apparatus after 4 days intensified training.
change from baseline Physical Performance (muscle power) 5days after the beginning of training	5days after the beginning of training	Peak lower body power will be measured by force platform after 4days-intensified training.

Trial Locations

Locations (1)

Goldring Centre For High Performance Sport; 🇨🇦 Toronto, Ontario, Canada