Plain English Summary
Background and study aims
Exercise and diet affect the muscles’ ability to make new proteins (muscle protein synthesis). Consuming protein after resistance exercise increases muscle protein synthesis (e.g., for building muscle). However, the best dose of protein to consume is not currently known. If too much protein is consumed, then the excess will be used for energy rather than for building muscle. This information is needed to improve diet and exercise strategies to increase muscle mass not only for healthy young exercisers, but also for helping more vulnerable groups, such as the elderly, to maintain muscle mass. The aim of this study is to determine the response of muscle protein synthesis to different doses of whey protein consumed at rest and following resistance exercise.
Who can participate?
Trained male weightlifters aged between 18-35, who have been doing resistance training for at least 6 months.
What does the study involve?
Participants are randomly allocated to consume one of four doses of whey protein after exercise. Chemical tracers are injected into the bloodstream for delivery to the muscle, and blood and muscle samples are taken to determine the rate at which muscle proteins were made following each dose of protein.
What are the possible health benefits and risks of participating?
The results of this study may help both young and old people who would benefit from muscle growth. The risks of participation include the potential for pain due to the vigorous exercise. However, we used trained experienced weightlifters for this study. Taking a muscle sample may cause pain or discomfort. Injecting the tracers can cause pain or discomfort through infection. However, this is extremely rare.
Where is the study run from?
University of Birmingham (UK).
When is the study starting and how long it is expected to run for?
December 2008 to June 2011.
Who is funding the study?
GlaxoSmithKline Nutritional Healthcare (UK).
Who is the main contact?
Dr Oliver C Witard
oliver.witard@stir.ac.uk
Trial website
Contact information
Type
Scientific
Primary contact
Dr Oliver Witard
ORCID ID
Contact details
University of Stirling
School of Sport
Stirling
FK9 4HG
United Kingdom
+44 (0)1786 466 298
oliver.witard@stir.ac.uk
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
N/A
Study information
Scientific title
Response of myofibrillar muscle protein synthesis to increasing doses of whey protein at rest and following exercise subsequent to a meal in resistance trained males
Acronym
Study hypothesis
Twenty grams of whey protein will be sufficient for the maximal stimulation of myofibrillar-muscle protein synthesis (MPS) rates at rest and after resistance exercise in trained, young adult males.
Ethics approval
National Research Ethics Service, Black Country, Birmingham, 08/02/2012, ref: 08/H1202/131
Study design
Parallel research design single-blind intervention study
Primary study design
Interventional
Secondary study design
Randomised controlled trial
Trial setting
Other
Trial type
Treatment
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet
Condition
Metabolic health of muscle / sarcopenia (age-related muscle loss)
Intervention
Each participant was randomly assigned to one of four groups. Each participant ingested one of four doses (0, 10, 20 or 40g) of whey protein after the exercise.
Intervention type
Supplement
Phase
Drug names
Primary outcome measure
Myofibrillar (contractile proteins) muscle protein synthesis
Secondary outcome measures
Amino acid concentrations
Overall trial start date
01/01/2008
Overall trial end date
01/06/2011
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. Male, aged 18-35 years
2. Healthy (no known metabolic disorder)
3. Experienced weight lifter for more than 6 months (at least 2 leg resistance training sessions per week)
Participant type
Patient
Age group
Adult
Gender
Male
Target number of participants
48 participants were completed
Participant exclusion criteria
Not simultaneously taking part in another scientific / clinical study
Recruitment start date
01/01/2008
Recruitment end date
01/06/2011
Locations
Countries of recruitment
United Kingdom
Trial participating centre
University of Stirling
Stirling
FK9 4HG
United Kingdom
Sponsor information
Organisation
GlaxoSmithKline Nutritional Healthcare (UK)
Sponsor details
GSK House
980 Great West Road
Brentford
Middlesex
London
TW8 9GS
United Kingdom
-
claire.2.lawrence@gsk.com
Sponsor type
Industry
Website
Funders
Funder type
Industry
Funder name
GlaxoSmithKline Nutritional Healthcare (UK)
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
Publication list
2013 results in: http://www.ncbi.nlm.nih.gov/pubmed/24257722
Publication citations
-
Results
Witard OC, Jackman SR, Breen L, Smith K, Selby A, Tipton KD, Myofibrillar muscle protein synthesis rates subsequent to a meal in response to increasing doses of whey protein at rest and after resistance exercise., Am. J. Clin. Nutr., 2014, 99, 1, 86-95, doi: 10.3945/ajcn.112.055517.