As someone who spends a great deal of my time sitting at a computer this story, which originally appears in the Sydney Morning Herald, gave my pause.  I’ll be making more of an effort to take hourly breaks from now on.

Sitting all day might significantly boost the risk of lifestyle-related disease even if you add a regular dose of moderate or vigorous exercise, scientists say.

The health benefits of pulse-quickening physical activity are beyond dispute – it helps ward off cardiovascular disease, diabetes and obesity, among other problems.

But recent scientific findings also suggest that prolonged bouts of immobility while resting on your rear end might be independently linked to these same conditions.

“Sedentary time should be defined as muscular inactivity rather than the absence of exercise,” a team of Swedish researchers concluded.

“We need to consider that we are dealing with two distinct behaviours and their effects,” they reported in the British Journal of Sports Medicine.

Led by Elin Ekblom-Bak of the Karolinska Institute in Stockholm, the scientists proposed a new “paradigm of inactivity physiology”, and urged fellow researchers to rethink the definition of a sedentary lifestyle.

They point to a recent study of Australian adults showing that each daily one-hour increase in sitting time while watching television upped the rate of metabolic syndrome in women by 26 per cent – regardless of the amount of moderate-to-intensive exercise performed.

Thirty minutes of daily physical exercise decreased the risk by about the same percentage, suggesting that being a couch potato can cancel out the benefits of hitting treadmill or biking, for example.

Metabolic syndrome is defined as the presence of three or more factors including high blood pressure, abdominal obesity, high cholesterol or insulin resistance.

New research is required to see if there is a causal link between being sedentary and these conditions and, if so, how it works, the researchers said.

One candidate is lipoprotein lipase, or LPL, an enzyme that plays a crucial role in breaking down fat within the body into useable forms.

Recent research has shown that LPL activity was significantly lower in rats with restrained muscle activity – as low as one-10th of the levels of rats allowed to walk about.

The LPL level during such activity “was not significantly different from that of rats exposed to higher levels of exercise”, the scientists reported.

“This stresses the importance of local muscle contraction per se, rather than the intensity of the contraction.”

These studies suggest that people should not only exercise frequently, but avoid sitting in one place for too long, they said.

Climbing stairs rather than using an elevator, taking five-minute breaks from a desk job, and walking when possible to do errands rather than driving were all recommended.

credit: smh.com.au

Advertisements