I have been gaining a lot of leg size over the last while without really trying, soon I am gonna be one of those guys that has to wear sweatpants all the time. I do not want to get there.

Any suggestions on the best way to maintain the legs at current or maybe back them down a bit without slowing my upper body growth? I have heard that you have to work the legs to get effective upper body growth.

Out of curiosity, how are you gaining so much leg mass? I need to know how to do that

I think mainly from walking everywhere, I moved downtown, got a job donwtown and parked the car now they are just bulking like crazy from my normal workouts and a couple of hours a day walking.

That's the first i've heard of that...how come? Anyone else heard this?

An old workout partner told me about working the legs adding to upper body growth (he had a long biology explanation for it), he's a doctor so I believed him, could be I'm incorrect.

Others seem to agree though as in this article.
http://www.bodybuilding.com/fun/lisa5.htm

Well doing exercises like squats, which use lower body and most of the torso, are supposed to really push the body to grow due to raising free testosterone levels, and releasing HGH.

Walking and distance running are not bulking exercises, they are endurance exercises and should not cause bulking.

I have added squats, deadlifts, and hack lifts back in to my plan in the last few months. Maybe if I lower my weights and lift them for endurance, would that keep the testosterone gains up?