Condition category
Nutritional, Metabolic, Endocrine
Date applied
24/06/2011
Date assigned
04/08/2011
Last edited
10/02/2016
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
People who do not do much physical activity or who accumulate excess body fat have an increased risk of diseases such as diabetes and cardiovascular disease. We do not really know why physical inactivity and/or eating more than you need increases risk of disease and we really need to find out more. We believe that chronic low-level inflammation and disturbed metabolism are critically important but it is very difficult to experimentally examine these pathways over a person's lifetime. Based on some recent research, we believe that we can simulate many of these changes through just a short-term intervention where we reduce a person's physical activity and give them more than they would usually eat. First of all, we need to see if the changes that we predict do actually take place and whether exercise can prevent these changes from taking place - and this is the purpose of the present study.

Who can participate?
We are looking for males, aged 18-40 years who are active (exercise more than 30 minutes per day, at least four times per week), who are non-smokers, not taking any drugs and whose weight has been stable for the last 6 months.

What does the study involve?
Participants will be asked to complete a range of preliminary tests (e.g., body mass, maximum oxygen uptake, body composition, habitual physical activity) after which they will complete a 1-week intervention.
Participants will be randomly allocated to one of two groups for the intervention. Both groups will be asked to reduce physical activity to <4000 pedometer steps per day for 7 days. During this period, one group will increase their energy intake by 50%. The other group will perform daily exercise at 70% maximum oxygen uptake for 45 min. This group will also increase energy intake by 50% above normal for 7 days but will also consume additional energy to offset exercise energy expenditure (and thus achieve the same energy surplus as the control group). Before and after the intervention, participants will come to the laboratory in the morning after an overnight fast. A cannula will be inserted for repeat blood sampling and an adipose tissue biopsy will be taken from abdomen. Participants will then consume a glucose-based solution and we will take blood samples over the following 2 hours.

What are the possible risks of participating?
1. Participants will be asked to complete a health questionnaire as well as a Physical Activity Readiness Questionnaire (PAR-Q) prior to participation in this study. The PAR-Q has been designed to identify the small number of adults for whom physical activity may be inappropriate or those who should have medical advice concerning the type of physical activity most suitable for them. In line with good practice, the laboratory is equipped with an automated defibrillator for use in the very unlikely event that resuscitation is required.
2. Participants will have to eat more food than normal. This might cause some inconvenience and discomfort.
3. Participants will have to temporarily interrupt normal exercise patterns and reduce other general physical activity in order to meet the 4000 step target. This might cause some inconvenience. Also, having to limit normal step count may affect some of the other activities that are normally performed (4000 steps would allow a typical office worker to go about their normal working life but not to undertake much additional walking or exercise).
4. A small fat sample will be taken at the beginning and end of the trial from around the waist. All fat samples will be taken by someone who has been specially trained to do so in order to minimise discomfort. There will be some bruising for a few days after taking this sample. There is a small chance of localised infection but good practice minimises this risk.
5. We will measure body fat using a very sophisticated and precise technique (dual energy x-ray absorptiometry or DEXA). DEXA is a non-invasive technique that uses a very low exposure to radiation. The radiation dose is often compared to the small exposure experienced during a short flight (e.g. London to Paris) and is similar to the amount of background radiation that would be received in a normal day living around Bath (and a tiny fraction [1/30th] of the amount of radiation experienced during a typical chest x-ray). This technique is routinely used in hospitals and with elite athletes but at the same time this does represent some exposure to a small amount of radiation. The risks associated with this amount of radiation are described as 'trivial' (less than 1 in ten million per whole body scan).

Where is the study run from?
The research will take place at the University of Bath.

When is study starting and how long is it expected to run for?
Participants can choose when to take part (i.e., the intervention can take place at a time that is convenient to them).
The study is expected to take place between September 2008 and September 2011.

Who is funding the study?
The University of Bath

Who is the main contact?
Dr Dylan Thompson
d.thompson@bath.ac.uk

Trial website

Contact information

Type

Scientific

Primary contact

Dr Dylan Thompson

ORCID ID

http://orcid.org/0000-0002-6312-1518

Contact details

Department for Health
University of Bath
Bath
BA2 7AY
United Kingdom
+44 1225 38 3177
d.thompson@bath.ac.uk

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

N/A

Study information

Scientific title

Can exercise overcome the effects of short term (one week) overfeeding and restricted physical activity on inflammatory markers and metabolic function?

Acronym

Study hypothesis

To determine if exercise can overcome the effects of a week of overfeeding and restricted physical activity on inflammatory markers and metabolic function in young, healthy, lean and active males?

Ethics approval

NHS Bath Research Ethics Committee approved on 19th March 2008, amendment approved on 3rd September 2008 (ref 07/H0101/234)

Study design

Randomised parallel group study

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Other

Trial type

Screening

Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet

Condition

Obesity

Intervention

Control:
1. Reduce physical activity to < 4000 pedometer steps per day for 7 days
2. Increase energy intake by 50% above normal for 7 days

Intervention:
1. Reduce physical activity to < 4000 pedometer steps per day for 7 days
2. Exercise daily at 70% maximum oxygen uptake for 45 min
3. Increase energy intake by 50% above normal for 7 days plus consume additional energy to offset exercise energy expenditure (and thus achieve the same energy surplus as the control group).

Intervention type

Other

Phase

Not Applicable

Drug names

Primary outcome measures

Changes in insulin sensitivity and glycaemic control. Measured at baseline and at the end of the intervention (i.e., after 7 days).

Secondary outcome measures

1. Other blood measures related to metabolic function and inflammation (e.g., cholesterol, Non-Esterified Fatty Acids [NEFA], Triacylglycerol, alanine aminotransferase [ALT], interleukin (IL)-6, leptin, adiponectin)
2. Changes in adipose tissue gene expression related to metabolic function and inflammation

Measured at baseline and at the end of the intervention (i.e., after 7 days).

Overall trial start date

03/09/2008

Overall trial end date

30/09/2011

Reason abandoned

Eligibility

Participant inclusion criteria

1. Male, aged 18 to 40
2. Physically active (more than 30 minutes per day 5 days per week)
3. Weight Stable (over the past 6 months)

Participant type

Patient

Age group

Adult

Gender

Male

Target number of participants

28

Participant exclusion criteria

1. Females
2. Smoker
3. Age outside range
4. Positive responses to Physical Activity Readiness Questionnaire
5. Taking medication
6. Doctor diagnosed condition that might interact with study measures (e.g. cardiovascular disease)

Recruitment start date

03/09/2008

Recruitment end date

30/09/2011

Locations

Countries of recruitment

United Kingdom

Trial participating centre

Department for Health
Bath
BA2 7AY
United Kingdom

Sponsor information

Organisation

University of Bath (UK)

Sponsor details

c/o Dr Dylan Thompson
Department for Health
University of Bath
Bath
BA2 7AY
United Kingdom

Sponsor type

University/education

Website

http://www.bath.ac.uk/

Funders

Funder type

University/education

Funder name

University of Bath (UK)

Alternative name(s)

Funding Body Type

private sector organisation

Funding Body Subtype

academic

Location

United Kingdom

Results and Publications

Publication and dissemination plan

Planned publication in a peer reviewed journal

Intention to publish date

31/12/2013

Participant level data

Available on request

Results - basic reporting

Publication summary

2013 results in http://www.ncbi.nlm.nih.gov/pubmed/24167223

Publication citations

Additional files

Editorial Notes

08/02/2016: Publication reference added. Verified study information with principal investigator.