If you think saying, "sitting is the new smoking," is alarmist, unscientific tripe, you need to spend more time reading health research. If that's not your speed, maybe you'll believe Mayo Clinic professor of medicine Dr. James Levine, who's told the world that sitting is more dangerous than smoking.
Either way, sitting too much is bad! As a sports medicine specialist, I can tell you there are other not-so-pleasant side effects when you set your bum in a chair for too many hours at a time. Sitting all day can cause things like neck pain, low back pain, knee pain, excess body fat around your middle, and poor flexibility in the legs and hips. At the young age of 30 you could find yourself feeling like an overweight, frail old person who's ready for a cane. Not a good look.
Fortunately, if you're someone who has to work a desk job, there's a super-simple exercise you can start doing right now to help counteract the negative effects of all that sitting. This exercise is the yoga squat, and all you have to do is take a few minutes to stand up from your desk every hour, and squat using the directions and picture guide below. Or even better, in addition to yoga squatting, also start taking short walks every hour to give your body a break from all that sitting.