You'll have to excuse the hyperbole, it's not a marketing shock tactic to get your attention, it's a genuine question whose answer may surprise you.
It's long been known that leading an inactive lifestyle is damaging to our health and well being, we get that, it makes sense, but the research coming out now is startling for two reasons -
1) Sitting down for prolonged periods is really really bad for us
2) Exercising doesn't undo the damage done from sitting down for too long
So how bad is really bad?
Well those of us who sit the most are twice as likely to develop diabetes and heart disease, arguably we have a cause and effect situation here, are they developing diabetes because of the sitting or is the sitting an effect of an unhealthy lifestyle and that's why they're developing diabetes, either way the link is there, inactivity = bad for us = increased risk of diabetes and heart disease.
How about the damage to muscles and bones?
Well it's not good here either, sitting hunched over a computer increases compression through the discs in the spine and can cause stiffness and pain, if unchecked it can lead to a disc prolapse, better known as a "slipped disc".
Ok ok I’m convinced sitting is bad for me, what can I do?
Well the good news is exercise isn’t the answer, it turns out the answer is simply getting up, every 30 mins just stand yourself up, go for a glass of water, a coffee, whatever it is, it simply stretches out our muscles and joints and prevents the damage.
This gets worse as we get older, our bodies age regardless of what we do but sitting for prolonged periods makes it worse, it’s not something that’s hard to remedy though. So if you don’t want your mobility and cognitive ability to suffer get up! That’s all there is to it and never watch a couple of TV programs without getting up