If you’re like most men living and working in a techno-service economy, you probably spend a good deal of your day sitting down. You go from the kitchen table to your desk at work to your chair in front of the TV. But as we’ve discussed before, spending most of your waking hours planted on your keister is terrible for your health.

You’ve probably experienced those moments when you get up from a sitting position and your butt feels numb and your hips feel so tight that you have to lean forward at the waist just to walk. Excessive sitting leaves your hips and legs tight and your glutes inactive. Even after you stand up, the ill effects of sitting stay with you and may prevent your butt muscles from firing at an optimal level when you really need them – like when you suddenly need to chase down a purse snatcher!

Some fitness experts argue that sitting causes muscles in the hip area to physically shorten (and stay shorter), even after you stand up. While there are no scientific studies to back that claim, from my own personal experience, sitting for lengthy periods of time definitely makes everything feel tight in the groin/butt area.

If you’re an athlete (or fancy yourself one), tight hips and inactive glutes can hamper physical performance in a variety of activities, such as sprinting, squatting, and — my favorite — deadlifting. If you want to perform at your best, you need to make sure that your hips stay limber and that your butt muscles are firing on all cylinders. Even if you’re not interested in deadlifting 600 lbs. (though I hope to change your mind on that someday), keeping your hip flexors loose and glutes active can improve your life on other fronts.
http://www.artofmanliness.com/2014/08/05/undo-the-damage-of-sitting/