ISRCTN - ISRCTN92528122: Growth of skeletal muscle in response to feeding different amounts of protein

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 measures

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

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 type

Industry

Website

http://www.gsk.com/

Funders

Funder type