If you're sitting down, you're a sitting duck After the age of 25, every hour of television you watch cuts another 22 minutes from your life. ARE you sitting down? Because I've got some bad news. Sitting down will kill you. Maybe not today, maybe not tomorrow, but later and for the rest of your life. It's not that your couch has a grudge; it's just that being inactive for long periods will shorten your life span according to a whole bunch of studies done by reputable universities. It's estimated that inactivity kills at similar rates to cigarette smoking (5.3 million people, according to The Lancet). When you sit down, you start burning calories only at a rate of less than one per minute. To put that into perspective, simply standing and doing nothing else will burn 10 per cent more calories; walking gently ups it 150 per cent. So if you sit a lot, then you're likely to get fat and die of heart disease. But it's not just the fat that will kill you. Sitting has other ways of ruining your health: it increases your risks of colon cancer, breast cancer, and type 2 diabetes. To put sitting into perspective, everything at home is trying to kill you and all you do will probably be fatal in some way. Last week a study showed that looking at room-level LED light (like on your phone or tablet) suppresses your melatonin levels, which will eventually cause cancer. We already know that eating charred foods, drinking artificially sweetened drinks and standing near inconsiderate bastards who smoke in public will also give us cancer. Frankly, it's a miracle any of us survive long enough to be able to sit down in the first place. The great news about the sitting part is, though, that it's easy to fix. You don't have to be the person who was killed by their favourite chair. Exercise is about a lot more than just looking pretty (and, frankly, we all have different ideas of what "pretty" is, so that's not really important). It's about literally saving your life. You don't have to do a thousand push ups and run a marathon. All you need is at least 30 minutes of intense exercise a week (preferably a day, but let's start slow) and to get up and do a lap of the room every 30-45 minutes. In our world full of TVs, computers and office jobs, incidental exercise can be hard to come by, because there are so many more entertaining things we could be doing. I play basketball and do long-distance running but, thanks to a life as a TV and video games reviewer, I'm still sitting for about nine-12 hours a day. Sitting for only six hours a day cuts nearly five years from your life expectancy and, after the age of 25, every hour of television you watch cuts another 22 minutes from your life. Basically, I'm screwed. I always felt that watching trashy reality TV was sucking my life force, but I thought that was metaphorical. Because I work from home, I can switch between my recliner and an exercise bike, which helps (After writing this, I think I'll make that switch more often). But those who work in an office are unlikely to have that luxury. Standing desks and even treadmill desks have become more popular in the last few years, so it might be worth talking to your boss about that. If your boss says no to such a lifesaving change, perhaps it's time to get creative. Put something that you sporadically need on the other side of the room, so you have to expend energy when you want to use it. Drink A LOT of water so that your bladder will take you frequently to the loo. Or get a Jawbone UP, or other fitness band; they can be set to vibrate if you've been inactive for more than half an hour, reminding you to jump or walk. There are also apps that can help, like 24/7 for the iPhone 5S. Most things that can extend your life require lots of effort or vegetables that taste like feet. This doesn't, not really. So, for your sake: get up, stand up. Stand up for your life. Alice Clarke is a freelance journalist. Find her on twitter @Alicedkc