I wasn't sure where to put this, but I was hoping to get some advice on strengthening my knees somehow.
I am a fairly inexperienced hiker, but in the last three months, I've gone on three hikes, a 10 mile 2-day in the NC mountains, a 20 mile 3-day in the Chisos mountains of Big Bend, and most recently 40 miles over 3.5 days down the Buckskin Gulch/Paria river.
On every hike, my knees have been absolutely killing me. While I have had some tendinitis in the past, it has never been anything like this. I do fine without a pack, but I think the added weight is the problem. Most trips have had 40-50lbs total pack weight including food, water, and clothes. Is there any way to build up my knees to get used to the weight? Should I just start going on regular walks around the neighborhood with my pack loaded up? I'd really like to do some longer trips, but I'm afraid to undertake much more distance with the pain I've been experiencing.

