One hour of moderate exercise a day enough to counter health risks from prolonged sittingBy cwan | August 2nd, 2017
Lack of physical activity has become a known risk factor for metabolic diseases and early death ever since a study back in 1953 showing that London bus drivers were at greater risk of heart disease compared to bus conductors. It is estimated that that more than 5 million people die globally each year as a result of failing to meet recommended daily activity levels. However, sedentary life style is a necessary phenomenon of the modern society. A typical day for many people is driving to work, sitting in an office, driving home and watching TV – many not by choice.
Facing with the dilemma from the modern life, a team of researchers from the Cambridge University asked the question: if an individual is active enough, can this reduce, or even eliminate, the increased risk of early death associated with sitting down?
In an analysis published in The Lancet, the Cambridge researchers analyzed 16 studies, which included data from more than one million men and women. The team divided individuals into four groups depending on their level of moderate intensity physical activity, ranging from less than 5 minutes per day in the bottom group to over 60 minutes in the top group. The researchers found that 60 to 75 minutes of moderate intensity exercise per day were sufficient to eliminate the increased risk of early death associated with sitting for over eight hours per day. Moderate intensity exercise was defined as equating to walking at 3.5 miles/hour or cycling at 10 miles/hour.
In addition, the researchers found that the greatest risk of early death was for those individuals who were physically inactive, regardless of the amount of time sitting. To be exact, this group is between 28% and 59% more likely to die early compared with the most active group — a similar risk to that associated with smoking and obesity.
This study suggests that lack of physical activity is a greater health risk than prolonged sitting. In another word, the culprit for the high incidence of metabolic diseases in modern society is the lack of physical activity, not the secondary lifestyle per se. For many of us who commute to work and have office-based jobs, there is no way to escape sitting for prolonged periods of time. The good news is that it is possible to reduce — or even eliminate — the risks associated with secondary lifestyles if we are active enough.
Thanks for reading.
Dr. Connie Wan
Journal Reference: Ulf Ekelund, Jostein Steene-Johannessen, Wendy J Brown, Morten Wang Fagerland, Neville Owen, Kenneth E Powell, Adrian Bauman, I-Min Lee. Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality? A harmonised meta-analysis of data from more than 1 million men and women. The Lancet, 2016; DOI: 10.1016/S0140-6736(16)30370-1