10:44pm Saturday 19 August 2017

Three hours of uninterrupted sitting damages blood vessels

The researchers used an experiment which involved 7-10 year old girls completing two 3-hour periods of sitting. One of these was uninterrupted and the girls sat for the entire three hours. The other was interrupted once an hour with a 10 minute moderate intensity exercise break. They assessed the health of the main artery in the leg before and after each of the 3-hour periods of sitting. Healthy artery function requires a balance in the dilation (enlargement) and constriction (narrowing) of the artery diameter, which helps to regulate blood flow. Uninterrupted sitting for 3 hours caused a 33% reduction in the ability of the artery to dilate (enlarge).  A 10-minute exercise break, however, was able to prevent this adverse impact of uninterrupted sitting.

Prolonged periods of sitting can have a detrimental impact on blood vessels and has previously been shown to even change the anatomy of limb arteries in adults and leads to increased cardiovascular disease risk. Dr Ali McManus, Centre for Heart, Lung and Vascular Health at the University of British Columbia and lead author of the study commented,

‘A sedentary lifestyle (excessive sitting) poses a huge health concern for adults and – as our study has shown – also for children. Only 7% of Canadian children now attain the recommended one-hour per day of moderate to vigorous physical activity and are spending up to 5 hours per day sitting.

‘Inactive children later become inactive adults. Inactivity is the fourth major risk factor for global mortality, contributing to 3.2 million deaths annually. Every parent should be asking ‘is the amount of time my child spends sitting harmful?’

She adds, ‘Our study has shown that three hours of uninterrupted sitting is harmful. We have also shown that interrupting sitting with regular exercise breaks prevents the negative health impact from too much sitting. A modest 10% reduction in sedentary behaviour has the potential to reduce direct health care costs by $150 million a year in Canada.’

‘Limiting the amount of time we spend sitting will not only result in lower health care costs and a larger and more productive workforce, but also in a reduced death and disability rate. This in turn will boost productivity and increase GDP and builds a strong case for action.

‘We only studied girls in this experiment. Future work will include boys and children who are at higher risk for excessive sitting. We will also explore whether the sitting induced reductions in leg blood flow are accompanied by altered brain blood flow and cognitive function. In the longer-term we will develop ‘inactivity’ surveillance and intervention tools for identifying children ‘at sedentary health risk’ and preventing excessive sitting.’



Notes to Editors

    Full paper title: McManus A et al (2015) Impact of prolonged sitting on vascular function in young girls. DOI: 10.1113/EP085355 http://onlinelibrary.wiley.com/doi/10.1113/EP085355/abstract
    Experimental Physiologypublishes high quality, original, physiological research papers that give novel insights into fundamental homeostatic and adaptive responses in health, and papers that further our knowledge of pathophysiological mechanisms in diseases. http://ep.physoc.or
    The Physiological Society brings together over 3,500 scientists from over 60 countries. The Society promotes physiology with the public and parliament alike. It supports physiologists by organising world-class conferences and offering grants for research and also publishes the latest developments in the field in its three leading scientific journals, The Journal of Physiology, Experimental Physiology and Physiological Reports. www.physoc.org

For further information please contact Dr Helga Groll, Media and Communications Officer.
Telephone: +44 (0)20 7269 5727 or email pressoffice@physoc.org.

Corresponding author: Dr Ali McManus, Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Canada

Tel: +1 250 807 8192, ali.mcmanus@ubc.ca

The Physiological Society

The Physiological Society is a company limited by guarantee. Registered in England and Wales, No. 323575. Registered Office: Hodgkin Huxley House, 30 Farringdon Lane, London, EC1R 3AW, UK. Registered Charity No. 211585.

The Physiological Society and The Physiological Society logo and The Journal of Physiology and The Journal of Physiology logo are trade marks belonging to The Physiological Society and are registered in the UK and in the EU Community respectively.

The contents of this email and any attachments are confidential. They are intended for the named recipient(s) only. If you have received this email in error please notify the system manager or the sender immediately and do not disclose the contents to anyone or make copies.

Share on:

MORE FROM Blood, Heart and Circulation

Health news