We don't have to like it but and not matter how active we think we are we all sit way to much. You can't help but be hit the face by that fact each and every day. Magazines have ad after ad for standing desks, desk treadmills, glut buster this, butt blaster that. The truth is sitting has become the new smoking.
Over the 25 years I was in practice I saw an every increasing number of people who could not properly active and fire their gluts. It seems like such an easy activity, just squeeze your butt, but try as they may they just couldn't do it. The young, the old, the fit and the unfit, the man or the lady, it didn't matter more often than not they couldn't squeeze those gluts. After awhile I took to calling it glut amnesia. It was like they forgot they even had a butt and were unable to activate the largest and most powerful muscle in the body.
In reality, the gluts are made up of three different muscles; the gluteus maximus, the strongest and largest of the group and the the muscle which gives your booty its shape and the gluteus medius and minimum, are the muscles which help to stabilize your hips/pelvis during any weightbearing activity.
So enough with the anatomy lesson and more to the question of what makes sitting so bad. Well, a few different things happen when we sit too much but to limit the length our discussion here I will focus on its affect on our ability to produce power in swimbikerun.
As we sit our hip flexors, muscles on the front side of your hips become shortened and tight, which leads to a forward tipped pelvis. In turn this causes your hamstring to be put under tension making them tight and weak, and your low back muscle are also shortened. Gradually your abs and gluts shut down by a process called reciprocal inhibition. In short, your powerhouse muscles don't fire, the body compensates by recruiting other muscles, which are not necessarily suited to do the job and your kinetic chain begins to breakdown. This means less power, more muscle soreness and an ever increasing risk for injury. Over time you develop what we call Lower Cross Syndrome(LCS).
I was lucky enough in my younger years to have studied under some of the forefathers of this concept, Drs. Vladimir Janda and Karel Lewit. While the name Lower Cross Syndrome came about much later the concept, the understanding of the dynamics of this issue have been around for decades. There is no x-ray, MRI or other magical test which determines the presence of LCS but rather as test as simple as looking at ones posture looking at the spinal curves or seeing if one can squeeze ones butt, not tighten the hamstrings, but SQUEEZE THE BUTT.
The good thing is that once you have figured out you have LCS it is reversible and fixable. First, get off your butt, don't sit for hours on end, but rather get up, move around, do something. Taking walking bathroom, get a drink of water, let the dog out break should be part or your routine. Next talk to your trainer, your coach, a good PT or chiro to help you with exercises to re-activate and strengthen the weakened muscles along with stretch and releasing the tight over active ones. While you can do this yourself it is difficult at first to know if you are actually activating the correct muscles, remember you got yourself to this spot in the first place so a little guidance in the beginning pays huge dividends in the long run. Finally, keep at it. Once the muscle have been either re-activated or deactivated you have to keep after it so they stays that way. Adding your glut exercises to your gym routine done a few times per week is enough to keep them firing along with a good hip flexor stretch to counteract all that sitting.
In closing, our sport is about the ability to produce power, if your main power generator isn't working you can't do that. With a little time, patience and effort on your part you will see your FTP increase and that PR is just around the corner, not BUTTS about it.