Even low levels of physical activity are linked to a reduced chance of dying from cancer, cardiovascular disease, and other illnesses, according to a new comprehensive research study published in the British Journal of Sports Medicine.
The research team analysed US data from 12 cross-sectional waves of the National Health Interview Surveys (NHIS) during 1997–2009, covering 88,140 eligible participants aged 40–85 years in the US, which they linked to the National Death Index records for mortality up to 31st December 2011.
” “Assuming causality of the associations we observed, both low and high levels of [physical activity] have beneficial effects on all-cause and cause-specific mortality risk. Importantly, vigorous [physical activity] has added benefits for reducing mortality compared with moderate [physical activity]. Promoting [physical activity] of any intensity and amount is an important approach to reducing mortality risk in the general population.”
– The study authors.
Study participants had answered two sets of questions to assess their frequency and duration of leisure time physical activity; physical activity (of at least 10 minutes) was categorized as vigorous (for example running, faster cycling and competitive sports, etc.) and light or moderate (eg, brisk walking, dancing, and gardening, etc.). The researchers used a combination of frequency (times/week) and duration (minutes/time) to define leisure time physical activity as measured in minutes/week units.
About 8,000 people died during the follow-up period. The researchers found that virtually any amount of exercise reduced the risks of dying of cardiovascular disease, cancer or any other cause. And these reductions in risk increased the more people exercised to an ultimate plateau; people who exercised more than 1,500 minutes a week had about the same risk of death, or slightly higher, than those who worked out a little less than that, according to the report.
Every extra hour of light activity above three hours reduced the risk of heart attack by about 15%. Light-intensity activity appeared to be important even when levels of higher-intensity physical activity were taken into account.
But what was perhaps most interesting was how little physical activity it took to see benefits. People who got just 10 to 59 minutes of light-to-moderate intensity physical activity during their free time each week had an 18% lower risk of early death than people who were sedentary. They also had a 12% lower risk of dying from cardiovascular issues during the study and a 14% lower risk of dying from cancer, the data showed.
Min Zhao et al. Beneficial associations of low and large doses of leisure time physical activity with all-cause, cardiovascular disease and cancer mortality: a national cohort study of 88,140 US adults doi: 10.1136/bjsports-2018-099254