Would you be surprised to learn that the answer to the question in the title of this article is "being a couch potato?" According to four papers published in a special July edition of the respected medical journal The Lancet, inactivity and living a sedentary lifestyle is now as great a risk to mortality worldwide as smoking.
One third of the adult population of the world – around 1.5 billion people – now get less than the minimum 150 minutes of moderate exercise per week that is recommended by public health authorities. This figure is even higher in adolescents, four out of five of whom now lead almost completely sedentary lives. Their inactive lifestyle means that the people who practice it now have a 20-30% higher risk of contracting life-threatening diseases than those who exercise regularly.
Research performed at Harvard Medical School and at Brigham and Women's Hospital found that approximately 6% of coronary heart disease and 7% of Type 2 diabetes worldwide comes from a lack of exercise. 10% of the cases of breast and colon cancer globally stem from physical inactivity. This resulted in 2008 in 5.3 million deaths linked to physical inactivity worldwide, as opposed to 5.1 million deaths that same year linked to smoking.
Inactivity is a global epidemic, but affects nations differently
Advances in technology – like cheap TVs, computers, and video games, combined with accessible transportation that means people don't have to walk as much when commuting to work or shopping – have given populations all over the world an easier lifestyle. Unfortunately, both in wealthy nations and in emerging nations, that easier lifestyle seems to be killing them.
In America, it is estimated that 43% percent of the population lead a basically inactive lifestyle, compared to 17% in Southeast Asia. The number of people living inactive lifestyles in Europe varies from country to country, ranging from highs of 70% in Serbia and Malta to lows of 18% in the Netherlands. Diseases and deaths related to inactivity also vary from area to area; in Europe researchers linked 121,000 deaths to inactivity in 2008, versus 44,000 in the eastern Mediterranean countries and 60,000 in North America for the same year.
This tragedy is preventable
Although the results of this research and the extent of the problem are disheartening, a solution to it is achievable. Governments and health care professionals, in conjunction with organizations like the Centers for Disease Control and Prevention, are developing strategies to convey to people the dangers of inactivity, urging them to get more exercise.
If their campaigns are successful, millions of lives could be saved. The researchers in The Lancet noted that if the current levels of physical inactivity were eliminated, the average life expectancy of the entire planet would go up by 0.7 years. That is a rate comparable to what would happen if public health officials found a way to completely eradicate either smoking, or obesity.
Because eliminating sedentary lifestyles completely is probably not in the picture, the researchers point out that if they were able to lower global inactivity by 10%, it would save 533,000 lives. If they could lower inactivity by 25%, 1.3 million deaths could be prevented.
This potential good news extends to us on an individual level as well. A recent study in the journal BMJ Open reported that if people were to limit the time they spent sitting to under three hours per day, they would add an extra two years to their lifespan. That's a lot of benefit from the simple act of getting up off of our butts.