Testing the activitystat hypothesis: a randomised controlled trial protocol

Gomersall, Sjaan, Maher, Carol, Norton, Kevin, Dollman, Jim, Tomkinson, Grant, Esterman, Adrian, English, Coralie, Lewis, Nicole, and Olds, Tim (2012) Testing the activitystat hypothesis: a randomised controlled trial protocol. BMC Public Health, 12 (851). pp. 1-110.

[img]
Preview
PDF (Published Version) - Published Version
Available under License Creative Commons Attribution.

Download (236kB) | Preview
View at Publisher Website: http://dx.doi.org/10.1186/1471-2458-12-8...
 
4
6


Abstract

Background: The activitystat hypothesis proposes that when physical activity or energy expenditure is increased or decreased in one domain, there will be a compensatory change in another domain to maintain an overall, stable level of physical activity or energy expenditure. To date, there has been no experimental study primarily designed to test the activitystat hypothesis in adults. The aim of this trial is to determine the effect of two different imposed exercise loads on total daily energy expenditure and physical activity levels.

Methods: This study will be a randomised, multi-arm, parallel controlled trial. Insufficiently active adults (as determined by the Active Australia survey) aged 18-60 years old will be recruited for this study (n=146). Participants must also satisfy the Sports Medicine Australia Pre-Exercise Screening System and must weigh less than 150 kg. Participants will be randomly assigned to one of three groups using a computer-generated allocation sequence. Participants in the Moderate exercise group will receive an additional 150 minutes of moderate to vigorous physical activity per week for six weeks, and those in the Extensive exercise group will receive an additional 300 minutes of moderate to vigorous physical activity per week for six weeks. Exercise targets will be accumulated through both group and individual exercise sessions monitored by heart rate telemetry. Control participants will not be given any instructions regarding lifestyle. The primary outcome measures are activity energy expenditure (doubly labeled water) and physical activity (accelerometry). Secondary measures will include resting metabolic rate via indirect calorimetry, use of time, maximal oxygen consumption and several anthropometric and physiological measures. Outcome measures will be conducted at baseline (zero weeks), mid-and end-intervention (three and six weeks) with three (12 weeks) and six month (24 week) follow-up. All assessors will be blinded to group allocation.

Discussion: This protocol has been specifically designed to test the activitystat hypothesis while taking into account the key conceptual and methodological considerations of testing a biologically regulated homeostatic feedback loop. Results of this study will be an important addition to the growing literature and debate concerning the possible existence of an activitystat.

Item ID: 37492
Item Type: Article (Refereed Research - C1)
Keywords: protocol, randomised controlled trial, physical activity, activitystat
Additional Information:

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

ISSN: 1471-2458
Funders: National Health and Medical Research Council (NHMRC), Australian Postgraduate Award Scholarship, Australian Research Council (ARC), South Australian Cardiovascular Research Development Program
Projects and Grants: NHMRC Project Grant #631916, NHMRC Training Fellowship #610312, ARC Postdoctoral Fellowship
Date Deposited: 04 Feb 2015 07:41
FoR Codes: 11 MEDICAL AND HEALTH SCIENCES > 1117 Public Health and Health Services > 111799 Public Health and Health Services not elsewhere classified @ 100%
SEO Codes: 92 HEALTH > 9204 Public Health (excl. Specific Population Health) > 920499 Public Health (excl. Specific Population Health) not elsewhere classified @ 100%
Downloads: Total: 6
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page