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Post-exercise Dietary Protein Strategies

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01319513
Recruitment Status : Completed
First Posted : March 21, 2011
Last Update Posted : March 21, 2011
RMIT University
Australian Institute of Sport
Nestec Ltd.
Information provided by:
McMaster University

Brief Summary:
Protein ingestion increases the rate at which the body builds new proteins in skeletal muscle (muscle protein synthesis. This study is designed to examine how the pattern of feeding affects muscle protein synthesis following resistance exercise. There is reason to believe that the large rapid increase in blood amino acid concentrations that accompanies the ingestion of a bolus of protein is important to increasing muscle protein synthesis. Thus, we hypothesize that the consumption a bolus of protein will elevate muscle protein synthesis to a greater extent than the consumption of an equivalent amount of protein that is consumed in small divided doses.

Condition or disease Intervention/treatment Phase
Optimal Anabolic Nutrition Interventions Other: whey protein bolus Other: whey protein pulses Not Applicable

Detailed Description:

The rapid appearance into the blood of essential amino acids, and leucine in particular, may act as an important signal to stimulate muscle protein synthesis after resistance exercise. This may explain why consuming rapidly-absorbed whey protein may have an anabolic edge over slowly-absorbed proteins such as casein. Previous investigations into importance of the rate of absorption to muscle protein synthesis that have used 'fast' and 'slow' proteins have been confounded by differences in amino acid composition. The present study addresses this issue by administering the same protein source, whey, as either a bolus or in small divided 'pulse' doses to achieve divergent amino acid profiles after a bout of resistance exercise.

This study is being conducted in young (18-35) men.

Our outcome measures include: blood amino acid concentrations, rates of myofibrillar protein synthesis, anabolic intracellular signalling markers

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 8 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Official Title: The Effect of the Pattern Post-exercise Aminoacidemia on Myofibrillar Protein Synthesis
Study Start Date : July 2009
Actual Primary Completion Date : October 2009
Actual Study Completion Date : October 2009

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: protein feeding
Participants will complete 2 trials in a cross-over fashion in which they will consume whey protein either as a single bolus or as 10 small divided doses
Other: whey protein bolus
single dose of 25 g whey protein

Other: whey protein pulses
10 2.5 g pulses of whey protein

Primary Outcome Measures :
  1. Rate of myofibrillar protein synthesis [ Time Frame: 4 months ]
    Rates of myofibrillar protein synthesis will be measured from muscle biopsy samples obtained from subjects participating in the study protocol.

Secondary Outcome Measures :
  1. Myocellular protein phosphorylation [ Time Frame: 4 months ]
    Protein phosphorylation of target proteins will be measured from Western blot analysis of muscle biopsy samples.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 35 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Non-obese men (BMI <27) between the age of 18 and 35 yrs.

Exclusion Criteria:

  • Type II diabetes or other known diseases
  • Use of medication
  • Female
  • Other ages or BMI than indicated above
  • Resistance training > 3X/wk

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01319513

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Canada, Ontario
Ivor Wynne Centre A103, McMaster University
Hamilton, Ontario, Canada, L8S 4K1
Sponsors and Collaborators
McMaster University
RMIT University
Australian Institute of Sport
Nestec Ltd.
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Principal Investigator: Stuart M Phillips, PhD McMaster University
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Dr. Stuart Phillips / Professor & Assoc. Chair Graduate Studies, McMaster University Identifier: NCT01319513    
Other Study ID Numbers: Darwin 1a - Bolus versus Pulse
First Posted: March 21, 2011    Key Record Dates
Last Update Posted: March 21, 2011
Last Verified: March 2011