Study also finds that 1 in 20 cases of cardiovascular disease could be prevented if everyone did 30 mins physical activity five days a week -- whether it's going to the gym, walking to work, or household chores
Completing 30 minutes of physical activity five days a week (150 mins a week) is associated with a reduced risk of death and cardiovascular disease, according to the largest study of physical activity tracking 130000 people in 17 countries published in The Lancet.
Being highly active (750 mins a week) is associated with an even greater reduction, and the authors found that this was more achievable for those who built physical activity into their day through active transport, job type, or housework.
The study confirms on a global scale that physical activity is associated with a lower risk of mortality and cardiovascular disease (including death from cardiovascular disease, heart attack, stroke, or heart failure), irrespective of a person's home country, other risk factors for disease, the type of physical activity and whether the activity is for leisure or if it is taken as part of daily transport, at work, or housework.
The World Health Organisation (WHO) recommend that adults aged 18-64 years old do at least 150 minutes of moderate-intensity aerobic physical activity throughout the week, as well as muscle strengthening exercises at least two days a week . But estimates suggest that almost a quarter (23%) of the world's population are not meeting physical activity guidelines.
Previous research into the benefits of physical activity has generally focussed on high-income countries, while research in low- and middle-income countries has been limited. Typically, studies also focus on exercise in leisure time, which is less common in lower-income countries.
"Meeting physical activity guidelines by walking for as little as 30 minutes most days of the week has a substantial benefit, and higher physical activity is associated with even lower risks," says lead author Dr Scott Lear, Professor of Simon Fraser University's Faculty of Health Sciences and Pfizer/Heart & Stroke Foundation Chair in Cardiovascular Prevention Research at St. Paul's Hospital in Canada. "The affordability of other cardiovascular disease interventions, such as generic drugs and consuming fruits and vegetables, are often beyond the reach of many people in low-income and middle-income countries. However, physical activity represents a low cost approach to preventing cardiovascular disease, and our study provides robust evidence to support public health interventions to increase all forms of physical activity in these regions." 
Cardiovascular disease is the leading cause of death worldwide and a major economic burden globally. It is estimated that 70% of cardiovascular disease deaths occur in low- and middle-income countries, where it is the most common cause of death.
In the study, 130843 participants aged 35-70 years old from urban and rural areas in 17 countries across various world regions  completed questionnaires on their levels of physical activity.
At the start of the study, each participant provided information on their socioeconomic status, lifestyle behaviours, medical history, family history of cardiovascular disease, weight, height, waist and hip measurements, and blood pressure. They also completed a questionnaire on the types of physical activity they completed over a typical week, which the researchers used to calculate their average activity levels.
Participants completed follow-up visits with the research team at least every three years to record information on cardiovascular disease and death for 6.9 years. The team analysed rates of cardiovascular events (including death from cardiovascular disease, heart attack, stroke, or heart failure) and deaths.
Of the 106970 people who met the activity guidelines, 3.8% developed cardiovascular disease, compared to 5.1% of people who did not (23549 people). Risk of mortality was also higher for people who did not meet the recommended amount of activity -- 6.4% compared to 4.2% for people who met guidelines.
The findings suggest that, if the entire population met physical activity guidelines, 8% of deaths (equivalent to around one in 12 cases) and 4.6% of cardiovascular disease cases (almost one in 20 cases) could be prevented. Furthermore, if the entire population was highly active (completing more than 750 minutes of physical activity a week), 13% of deaths (around one in 8 cases) and 9.5% of cardiovascular disease cases (around one in 10) could be prevented.
Overall, almost a fifth of people in the study (18%, 23631 people) did not meet the physical activity guidelines, but almost half (44%, 57868 people) were highly active.
Physical activity as transport, occupation or housework was the most common form of physical activity, across all regions (ranging from 437 to 574 minutes per week). While physical activity in leisure time was common in high-income countries (average of 130 minutes per week), it was rare in other regions (25 minutes a week in lower-middle income countries and no time spent in this way in upper-middle- and low-income countries).
Overall, the more activity a person did the lower their risk of mortality and cardiovascular disease -- with the study finding no ceiling effect on the association, and no risks associated with extremely high levels of physical activity (more than 2500 minutes per week, up to 17 times the physical activity guideline amount).
The authors recommend building physical activity into one's daily lifestyle to achieve higher levels and reduce risk as much as possible.
"Our study found that high physical activity was only possible in people who completed physical activity as a form of transport, part of their job or through housework -- with 37.9% people who acted in this way attaining this level of activity, compared to 2.9% who were only physically active in their leisure time. This reflects the challenge of trying to be highly active during limited daily leisure time outside of work and domestic duties," says Dr Lear .
The authors note that the physical activity questionnaire used in their study may overestimate the amount of physical activity completed, meaning the benefits of exercise could be even higher than projected in the study.
Writing in a linked Comment, Dr Shifalika Goenka, Indian Institute of Public Health-Delhi (IIPH-D), Public Health Foundation of India (PHFI), and Centre for Chronic Disease Control (CCDC), India, says: "Cardiovascular disease is known to have devastating effects on individuals and families. In low-income and lower-middle-income countries, cardiovascular disease can push people to below the poverty line... Creating a physical, social, and political environment where physical activity in daily living is desirable, accessible, and safe should be a developmental imperative... Promotion of physical activity, active transport, and active living by means of interventions contextualised to culture and context will have powerful and long-lasting effects on population health and developmental sustainability."
NOTES TO EDITORS
The study was funded by Population Health Research Institute, the Canadian Institutes of Health Research, Heart and Stroke Foundation of Ontario, Ontario SPOR Support Unit, Ontario Ministry of Health and Long-Term Care, AstraZeneca, Sanofi-Aventis, Boehringer Ingelheim, Servier, GSK, Novartis, King Pharma, and national and local organisations in participating countries that are listed at the end of the Article. It was conducted by researchers from Simon Fraser University, Providence Health Care, Hamilton Health Sciences & McMaster University, University of Edinburgh, Aga Khan University, St John's National Academy of Health Sciences, Madras Diabetes Research Foundation, Postgraduate Institute of Medical Education & Research, University of Gothenburg, Fu Wai Hospital, Xishuangbanna Prefecture, Government Medical College, Estudios Clinicos Latinoamerica ECLA, Dubai Health Authority, Eternal Heart Care Centre & Research Institute, Isfahan University of Medical Sciences, Medical School Universidad de Santander, Istanbul Medeniyet University, Medical University of Wroclaw, Universidad de La Frontera, Dante Pazzanese Institute of Cardiology, and Institut universitaire de cardiologie et de pneumologie de Québec.
 WHO guidelines available here: http://www.who.int/dietphysicalactivity/publications/9789241599979/en/
 Quote direct from author and cannot be found in the text of the Article.
 Three high-income countries (Canada, Sweden, United Arab Emirates); seven upper-middle-income countries (Argentina, Brazil, Chile, Poland, Turkey, Malaysia, South Africa); three lower-middle-income countries (China, Colombia, Iran); and four low-income-countries (Bangladesh, India, Pakistan, Zimbabwe).
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