People who spend more than seven hours a day in front of a computer or television screen are 85% more likely to die prematurely from heart disease. Lack of physical activity is directly responsible for more than five million deaths worldwide each year, as many as smoking. A study published in the prestigious Journal of the National Cancer Institute, which compiles multiple studies carried out over the past few years, indicates that people who do very little physical activity are considerably more at risk of being affected by certain types of cancer.
Barely 15% of the population does the recommended minimum of 150 minutes of moderate-intensity physical activity per week. On average, it is estimated that an adult devotes almost 10 hours of his waking period each day to sedentary activities, devoid of any physical exertion!
This is a completely abnormal situation, which even goes completely against the needs of our body: the approximately 640 muscles and 206 bones, which alone account for half of body mass, do not weren’t selected by evolution for us to sit in a car, in front of a computer or a television for most of the day! We are not only born to think and innovate, but also, and perhaps above all, to move, which we have done throughout human history.
Screen all day: 85% more risk of premature death
The importance of being active for maintaining good health is well illustrated by the significant reduction in the risk of certain cancers (breast, colon, uterus, lung, prostate) in people who regularly engage in physical activity.
In addition to preventing people from taking advantage of the reduction in cancer risk brought about by physical activity, physical inactivity causes health problems of their own, independent of those caused by lack of exercise. For example, several studies have shown that time spent in sedentary activities is associated with a dramatic increase in the risk of premature mortality: people who spend more than seven hours each day in front of a computer or television screen have 85% more more likely to die prematurely from heart disease and 22% more likely to die from cancer than those who watch less than an hour a day.
Cancer loves being sedentary
The negative impact of a sedentary lifestyle on the risk of cancer was confirmed by the analysis of the results obtained by 43 different studies, relating to a total of 68,936 cases of cancer. The researchers found that a sedentary lifestyle was associated with a 24% increased risk of colorectal cancer, 32% increased risk of uterine cancer and 21% increased risk of lung cancer. This increased risk is even more pronounced when inactive moments are devoted to watching television, with an increase of 54% for colorectal cancer and 66% for uterine cancer. There is therefore no doubt that the great sedentary lifestyle of modern societies contributes to the high incidence of these cancers in the population.
8h sitting at work + 4 hours of TV in the evening = 12h inactive per day
To prevent cancer, it is therefore necessary not only to be physically active, but also to avoid being too sedentary the rest of the time as much as possible. For example, a person can do half an hour of brisk walking every morning (and therefore respect the recommendations of 150 minutes of physical activity per week), but if they sit all day at the office and spend the evening in front of the television , she can devote more than 12 hours of her waking period to passive activities. In other words, what is considered to be an active person, according to current criteria, may actually be active for only 3% of their available time!
Talk standing on the phone, 5 min break every hour and walk at lunch break
It is therefore absolutely necessary to find a way to use the approximately 15 hours that remain at our disposal to be more physically active, if only by avoiding sitting for long periods as much as possible. All means are good: talking standing on the phone, taking a break of a few minutes every hour to drink water, walking outside during the lunch break, keeping light weights handy when you have to read a text, etc.
The most important thing is to realize that a sedentary lifestyle is an abnormal behavior, completely unsuited to human physiology, and to avoid as much as possible remaining inactive for too long, whatever the type of activity carried out.
Schmid D and Leitzmann MF. Television viewing and time spent sedentary in relation to cancer risk: a meta-analysis. J. natl Cancer inst.