Sun | May 19, 2019

The Tranquil Way | The hazards of sitting

Published:Tuesday | January 10, 2017 | 12:00 AM

A sedentary lifestyle is well known to be associated with poor health outcomes. Of course, logically, the thinking was that this was because these persons are not getting enough exercise. Recently, it was found, though, that there is more to it than just that.

There is no doubt that exercise improves health. The normal recommendation is 20-30 minutes of moderate exercise four to five times weekly. Up to one hour is acceptable. The best forms of exercise are those that keep the heart rate elevated (50 - 80% of maximal heart rate, which is 220 minus your age) continuously for the duration of the exercise. These include cycling, walking, swimming, jogging, and aerobics.

It was thought that once you put in enough exercise into your routine, then this would nullify the effects of an otherwise sedentary lifestyle. In other words, getting some exercise in the morning and then sitting down at a desk job all day should be okay, right? Not so, was the conclusion of a recent analysis. The exercise that is done does not totally nullify the effect of sitting all day. There is benefit, though, of getting exercise over not getting any at all.

So sedentary living and scheduled exercise are independent factors that have opposing effects. This means that apart from getting regular, scheduled exercise, we need to incorporate increased mobilisation during the day and do less sitting. Increased sitting has been associated with higher overall death rate, risk of diabetes, heart disease, stroke, cancer, etc.

It is now known that the contraction of muscles releases anti-inflammatory substances into the bloodstream, which reduces the risk of the development of chronic illnesses and their complications. The more sitting that is done will, of course, reduce the amount of muscular contraction that takes place and, thereby, allow inflammation to rise.

For persons who have a desk job, this information is important. It's important to monitor the number of steps taken each day, but it has been suggested that even simple standing may help as this will involve muscular contraction. More studies will, of course, need to be done to find out what the optimal levels of activity are. Some authorities recommend 10,000 steps per day. Some cell phones have an app that can monitor this. Other recommendations include sitting for two to three hours less each day and getting up and moving around every half hour.