An Hour a Day is Enough

The health risks associated with sitting for eight or more hours a day can be eliminated with an hour or more of physical activity a day.

Current physical activity guidelines from the World Health Organisation (WHO) recommend that adults do at least 150 minutes (5 x 30mins) of moderate intensity exercise per week. It is also well known that being physically inactive increases the risk of chronic diseases, including diabetes mellitus, cancer (colon and breast), obesity, hypertension, bone and joint diseases (osteoporosis and osteoarthritis). However, according to a report conducted by the Hong Kong Sports Commision (2009), the physical activity level of 51% of Hong Kong people did not meet the “baseline indicator” (i.e. participating in physical activities of moderate- or vigorous-intensity at least three times a week, with an accumulation of at least 30 minutes a day).

Research published in The Lancet looked at a number of existing studies and attempted to answer the question of how much exercise is required to balance the negative effects of prolonged sitting.  

In total the researchers analysed 16 studies, which included data from more than one million men and women. They found that 60-75 minutes of moderate intensity exercise per day was sufficient to eliminate the increased risk of early death associated with sitting for over eight hours per day.  

The research concluded that those that were physically inactive had a 28-59% greater risk of early death, regardless of the amount of time sitting compared with those who were the most active. Interestingly this risk is similar to that associated with smoking and obesity. This suggests that even though we know that prolonged sitting is detrimental to our health, being physically inactive seems to be a bigger concern regarding health.

• 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-