Everyone has a general understanding of the importance of exercise but there is often some confusion surrounding the specifics of what it means to be physically active. I have compiled the following list to help summarise the research surrounding this topic.
Physical Activity- An Overview
What is physical activity?
Physical activity can be defined as any bodily movement caused by the contraction of skeletal muscle that results in energy expenditure above resting levels. In the Health Survey for England (2013)1 our physical activity levels are classified as follows;
- Meeting recommendations: 150+ minutes a week of moderate-intensity activity or 75+ minutes of vigorous-intensity in bouts of 10 minutes or more.
- Some activity: 60-149 minutes a week of moderate-intensity activity or 30-74 minutes of vigorous-intensity.
- Low activity: 30-59 minutes a week of moderate-intensity activity or 15-29 minutes of vigorous-intensity
- Inactive: less than 30 minutes a week of moderate-intensity activity or less than 15 minutes of vigorous-intensity.
What does physical inactivity cost us?
The Department of Health (2011)1 states the estimated direct cost of physical inactivity to the NHS is £1.06 billion. They claim this is a conservative estimate as it is based on only five conditions, and excludes the costs of other diseases and health problems. Public Health England (2014)2 declares the yearly cost to the NHS and wider society is £7.4 billion, although it has been suggested elsewhere that the direct and indirect costs of inactivity in the UK total £20 billion a year (HM Government/Mayor of London, 2014)3. UKActive (2014)4 predict that a 1% reduction in inactivity could save £1.2 billion over five years.
Why be active?
The health benefits of living a physically active lifestyle have been well-publicised and its importance is seemingly universally acknowledged, supported by a considerable evidence-base. Yet a significant number of us are still inactive. The World Health Organisation (2014)5 state that roughly 3.2 million deaths occurring each year can be attributed to physical inactivity and consider it the fourth leading risk factor for global mortality. Public Health England (2014)6 claim that physical inactivity is responsible for 1 in 6 (17%) of UK deaths, making inactivity as dangerous as smoking.
How active are we?
The HSCIC (2014)7 report that in 2012, self-reported measures of physical activity indicate that two-thirds of men and just over half of women are currently meeting the current UK guidelines. However, they also report that objective measures (using accelerometers) in 2008 show that only 6% of men and 4% of women met the guidelines – a considerable difference. The main issue cited was that most physical activity was sporadic and less than the recommended minimum bouts of 10 minutes or more. This would seem to imply that a sizeable proportion of the UK population is inactive. Self-reports indicated 26% of women and 19% of men were classified as inactive (doing less than 30 minutes of moderate-intensity activity in a week)7 More objective measures may well reveal these to be far higher.
How active should we be then?
For adults aged 19-64 years, it is recommended we are active daily, accumulating at least 150 minutes a week of moderate-intensity activity in bouts lasting a minimum of 10 minutes. We can get comparable outcomes with 75 minutes a week of vigorous activity. In addition, we should incorporate activities that improve muscle strength at least twice a week, and minimise the time we spend being sedentary for long periods (Department of Health, 2011).
What is the difference between moderate and vigorous intensities?
Moderate-intensity activities result in you breathing faster, but you should still be able to hold a conversation; you will also experience a noticeable increase in heart rate, feel warmer and maybe even sweat on hot or humid days. Whereas vigorous-intensity activity results in you having a substantial increase in heart rate, rapid breathing and a shortness of breath, so you cannot hold a conversation comfortably.
References
- http://www.hscic.gov.uk/pubs/healthsurveyeng13
- https://www.gov.uk/government/publications/start-active-stay-active-a-report-on-physical-activity-from-the-four-home-countries-chief-medical-officers
- https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/366522/141022_EAED_MP_toolkit.pdf
- https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/279657/moving_living_more_inspired_2012.pdf
- http://ukactive.com/downloads/managed/Turning_the_tide_of_inactivity.pdf
- http://www.who.int/topics/physical_activity/en/
- https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/353384/Everybody_Active__Every_Day_evidence_based_approach_CONSULTATION_VERSION.pdf
- http://www.hscic.gov.uk/catalogue/PUB13648/Obes-phys-acti-diet-eng-2014-rep.pdf
