We stand around a lot here at 
Men’s Health. In  fact, a few of us don’t even have office chairs. Instead, we write,  edit, and answer e-mails—a lot of e-mails—while standing in front of our  computers. All day long. Why? 
It all started last summer, when Assistant Editor Maria Masters came across a 
shocking study in the 
Medicine & Science in Sports & Exercise  (one of dozens of research journals we comb each month as we put  together the magazine). Scientists at the Pennington Biomedical Research  Center in Louisiana analyzed the lifestyles of more than 17,000 men and  women over about 13 years, and found that people who sit for most of  the day are 54 percent more likely to die of heart attacks.
That’s right—I said 54 percent! 
Masters  immediately called the lead researcher at Pennington, a professor named  Peter Katzmarzyk. Turns out, this wasn’t the first study to link  sitting and 
heart disease.  Similar research actually dates back to 1953, when British researchers  found that (sitting) bus drivers were twice as likely to die of heart  attacks as (standing) trolley operators.
Here’s the most surprising part: “We see
 it in people who smoke and people who don’t,” Katzmarzyk told Masters. “We see it in people who are 
regular exercisers and those who aren’t. Sitting is an independent risk factor.”
In  other words, it doesn’t matter how much you exercise or how well you  eat. If you sit most of the day, your risk of leaving this world  clutching your chest—whether you’re a man or women—as much as doubles. 
This  raised a rather obvious question: Why? Truth is, the researchers aren’t  sure. But Marc Hamilton, Ph.D., one of Katzmarkzyk’s colleagues,  suspects it has to do with an 
enzyme  called lipoprotein lipase (LPL), which breaks down fat in the  bloodstream and turns it into energy. Hamilton found that standing rats  have ten times more of the stuff coursing through their bodies than  laying rats. It doesn’t matter how fit the rats are; when they leave  their feet, their LPL levels plummet. Hamilton believes the same happens  in humans.
Still sitting? Then you should know that your office chair also: 
1. Screws up your posture.  The fascia, the tissue that connects individual muscles into a  full-body network, begins to set when you stay in one position for too  long, says 
Men’s Health advisor Bill Hartman, P.T., C.S.C.S., a  physical therapist in Indianapolis. If you’re hunched over a keyboard  all day, this eventually becomes your normal posture.
2. Makes you fatter.  This happens for two reasons. First, you burn 60 more calories an hour  when standing versus sitting. But more importantly, says Hartman, when  you spend too much time sitting, your largest muscle group—the glutes  (a.k.a. your butt)—become lazy and quit firing. This is called gluteal 
amnesia. And it means you burn fewer calories.
3. Causes lower back pain.  Weak glutes push your pelvis forward, putting stress on the spine, says  Hartman. Here’s the other unseemly thing that happens when your pelvis  tilts forward: Your belly protrudes, making you look 5 months 
pregnant. 
So  what’s a desk-bound worker to do? First, Hamilton suggests you change  how you think about fitness. We have a tendency to segment our  lives—work, home, and downtime. Exercise falls into the last category,  something we squeeze into our busy schedules when possible. But if you  stop thinking about exercise as an activity, and instead think of it as a  lifestyle, it’s easier to make healthy choices throughout the day. 
In other words: Stop trying to be fit, and start trying to live fit.
Second, of course, is to stand more throughout the day. These strategies will get you up on your feet more often: 
Strategy #1: Take  two breaks an hour. Grab a drink from the water fountain. Pop over to  the cube next door to say hi. Or simply stand and stretch for a minute. A  
European Heart Journal study of 5,000 men and women found that  the quarter who took the most breaks during the day were 1.6 inches  thinner than the quarter who took the least.
Strategy #2: Stand  during phone calls. It may seem like a small thing but, as Hamilton  told Masters: “Small choices will help move you in the right direction. .  . . It all adds up, and it all matters.” 
Strategy #3:  Don’t write long emails. If crafting an email will take longer than 15  minutes, go talk to the person instead. Or stand up and call them.
And if that’s not enough (and it may not be) . . .
Strategy #4: Ask  HR for a standup desk. Australian researchers found that workers who  log more than 6 hours of seat time a day are up to 68 percent more  likely to be overweight. If you make the changes above and your  waistline isn’t shrinking, a standup desk may be the answer. Make sure  the screen is at arm’s length, and the top at eye level. Position the  keyboard so your elbows are bent 90 degrees. 
Men’s Health Senior Editor Bill Stieg built his own.
Source : 
Yahoo Health.