Bloggers, too much sitting can offset the benefits of regular exercise

Participation in sport is associated with a with a 20—40% reduction in all-cause mortality compared with non-participation. Exercise might also be considered as a fifth vital sign, according to the Lancet: http://goo.gl/gyxYf

From the NYTimes:

Wrong: Sitting at your cubicle. Better: Walking while clicking and talking.

Your chair is your enemy.

It doesn’t matter if you go running every morning, or you’re a regular at the gym. If you spend most of the rest of the day sitting — in your car, your office chair, on your sofa at home — you are putting yourself at increased risk of obesity, diabetes, heart disease, a variety of cancers and an early death.

In other words, irrespective of whether you exercise vigorously, sitting for long periods is bad for you.

If you need any more convincing, please see this Thai Health Promotion Foundation video that clearly shows the benefits of exercise:

References:

Stand Up While You Read This! - Opinionator Blog - NYTimes.com
How to Exercise WHILE Blogging or Doing Other Computer Work