I'll let you know how my rehab goes......
Now that I have your attention, For the last few years I've been keeping a weekly activity log, monitoring how much I walk, jog, hike, bike & spend on a treadmill. In 04, 05 & 07 I average a weekly total of 12.5 to 14 miles. (roughly 4 on treadmill & the rest walking hiking, jogging - hike once a month unless I sneak out for another day)
In 2006 & 2008 I averaged between 21 & 22 miles a week (8+ miles on the treadmill, 7 walking 3.5 hiking & a 1.5 or so jogging, biking (biking is at 1/2 actual distance to try & equate the effort to the other activities) etc.
In 2006 & in November 2008, I developed knee pain. In 2006, taking it easy in December, January & much of 2007 helped. This time I saw the MD's. (My volleyball team has moved up & we are trying to move to the A league so taking time off is not an option. VB is my other passion & knee most troublesome walking uphill & jumping) I did not want to push through a tendon or ligament injury & end up off my feet for months.
Diagnosis, muscles around knee are not of equal strength & therefore, knee is being pulled off it's normal tract. To make up for some free space in the knee, I've developed a bone spur that's digging into the cartidge when aggravated. Cure - more stretching & rehab to learn exercises to build up muscles so knee gets back to normal. (I report back on exercies but suspect some light weight training. My history, 37 years of playing, hoop, VB, soccer, hiking, a gym class jock, some school sports, CYO BB but never a star now a 225 lb weekend & lunch time (treadmill) warrior - & Dad - denying I'm closer to 50 than 40.
Or not much different, weight aside maybe, then many of us.
I suspect weight training, especially legs (& some shoulders & back) will help. You don't have to squat 400 pounds or lift the entire weight stack on the leg extension machine. In fact form is better than weight - as opposed to some people you see in the gym jerking large weights with all their body instead of isolating the intended muscle groups. if that was benefical I'd quit the gyn & push my car up the driveway