I'm one if the folk who's been posting about sore knees. I started in September and got as far as w3r2 when I got a really sore and stiff knee (sort of a pinched pain, not the standard background "growly pain" that I've been getting for years. I also couldn't straighten my leg completely and had to sleep with a pillow under my knee for a couple of nights.) Several trips to doctor and some x-rays later I have discovered:
* I likely damaged a miniscus by "overdoing" it (ie not taking the rest days) This explains the "pinched" pain
* I have moderate osteoarthritis in both knees (explains growly pain)
* my kneecaps are in the wrong place - probably since birth - which makes them more succeptible to damage
So I now have a referral to a podiatrist to get proper insoles (did I say I also have wonky feet), a referral to a physio to get knee strengthening exercises (meantime I'm doing the ones from the NHS site). I am also taking 1000mg of cod liver oil per day. (GP was actually muttering about surgery to try to realign kneecaps, but I don't feel like I'm in enough pain often enough to warrent that !)
Being a stubborn type I want to give it another go. Yesterday I went out and just made sure I can walk for 30 minutes briskly without hurting my knee. My idea is that if I still don't have any pain at the weekend, I will try w1r1 again.
I aggravated things last time round by going out anyway despite a niggly pain. I know better now and will definately observe the rest days. If I have the same problem again despite this, then I'll look for a different exercise regime. I guess I'll also abide by my physio's opinion.
Any comments/advice welcome especially from anyone who has similar knee problems.