It has been gold standard wisdom — stamped by the World Health Organisation (WHO), no less — that a half hour of moderate exercise a day goes a long way in keeping cardiovascular disease (CVD) at bay. However, the evidence for this was based on studies in western Europe and the United States and on people who took time out of their routine to exercise. In a study published in The Lancet last week, that panned 17 countries and over a 100,000 people including India, a team of experts have established these benefits across populations. Even better, they report, exercise doesn’t necessarily mean a tedious treadmill routine but can include physical activity performed while tidying up your house, commuting to work and even tending to your plants.
There was also no such thing as ‘too much exercise’, and working out an hour-or-so over the minimum meant even more protection against CVD, including death from cardiovascular disease, heart attack, stroke, or heart failure, and reduced overall mortality in the sample of people studied.
Of the 1,06,970 people studied over seven years who conformed to the norms of various grades of exercise (moderate, heavy), the risk of mortality was higher for people who did not meet the recommended amount of activity — 6.4% compared to 4.2% for people who met guidelines. Also only 3.8% of those who met exercise criteria developed CVD compared to 5.1% of people who did not meet exercise requirements.
Dr. R.M. Anjana, diabetologist at the Madras Diabetes Research Foundation, said the benefit was “statistically significant” given the large sample size involved. A co-author of the study, she said that the study underlined the importance of integrating any form of physical activity into one’s daily routine. “Previous studies have focussed on western populations exercising in their leisure time. In countries such as India, a lot of physical activity is part of work schedules and yes, that too contributed to a reduced risk of CVD,” she told The Hindu. However the researchers didn’t break down the health gains by country and instead “pooled” data across low-income and high-income countries.
Were the entire population to meet 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.
The WHO recommends that adults aged between 18-64 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 nearly a quarter of the world’s population is not meeting physical activity guidelines.
The benefits of moderate exercise were significant — or nearly 20% in reducing CVD risk — over not exercising, says Shifali Goenka, a specialist in non-communicable diseases at the Public Health Foundation of India, and who independently reviewed the study. “The work shows how important it is to have better infrastructure and investment in community health,” she added.
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.
For the analysis, 130,843 participants aged between 35-70 from urban and rural areas in 17 countries across the world 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.
Overall, almost a fifth of people in the study — (18%, 23631 people) — did not meet physical activity guidelines, but almost half — (44%, 57868 people) — were highly active.