This may seem like a weird question...but what about lying down or reclining as opposed to sitting? Does it have the same disadvantages?
I'm a highly active person with regular exercise (weights, cardio, etc.) but I'm also in sedentary IT and have a setup that allows me to recline/lie down when I'm not standing.
I basically decided years ago when I started having lower back issues (despite the healthy BMI/activity level) to declare war on "sitting" and only do it when I absolutely have to (driving/social functions etc.).
Reclining/lying down while working (coupled w/ standing) at least for me eliminated all of these issues and I'm now curious if it would eliminate the sitting related sperm count issues as well.