In an issue of the British Journal of Sports Medicine, specialists argue that prolonged periods of sitting are truly detrimental. In addition, we should focus on the harms caused by daily inactivity rather than on the lack of regular exercise alone.
The term “sedentary behavior” has come to mean “taking no exercise” according to doctors from the Karolinska Institute and the Swedish School of Sport and Health Sciences in Stockholm, Sweden.
They say it should be more correctly used to describe “muscular inactivity.”
Recent research indicates that prolonged periods of sitting and lack of whole body muscular movement are strongly linked to obesity, diabetes, heart disease, cancer, and an overall higher risk of death. This is regardless of whether moderate to vigorous exercise is taken.
An Australian study suggested that for every additional hour a woman sits in front of the TV, her risk of metabolic syndrome which is a precursor to diabetes and cardiovascular disease, increases by 26 percent. This is irrespective of how much moderate exercise she does.
The authors explain that the health of people who already do too little exercise will suffer even more if combined with extended bouts of sitting.
The researchers remark that further investigation is needed to establish a causal effect between prolonged sitting and ill health. However, some underlying mechanisms have already been identified. These include an enzyme known as lipoprotein lipase. It has an essential role in the regulation of key blood fats.
Consequently, the authors put forward a new model or paradigm of “inactivity physiology“. It establishes that sitting and non-muscular activity may independently boost the risk of ill health, and that sedentary behavior is a separate class of behavior with specific consequences for ill health. These are different than those caused by taking too little exercise.
The authors explain that the molecular and physiological responses of the body provoked by too much sitting cannot simply be eliminated by taking additional exercise.
They add: “In the future, the focus in clinical practice and guidelines should not only be to promote and prescribe exercise, but also to encourage people to maintain their intermittent levels of daily activities [that involve movement]. Climbing the stairs, rather than using elevators and escalators, five minutes of break during sedentary work, or walking to the store rather than taking the car will be as important as exercise.”
“Are we facing a new paradigm of inactivity physiology?”
Elin Ekblom-Bak, Mai-Lis Hellénius, Björn Ekblom
Online First 2010;
doi 10.1136/bjsm.2009.067702 (resource no longer available at press.psprings.co.uk)
British Journal of Sports Medicine
Written by Stephanie Brunner (B.A.)