Hello. I am training for my first marathon, and on my longest training run last weekend of 20 miles, my knees began to hurt at about mile 12. They continued. I had to stop and stretch frequently. I finished the 20 miles, but at mile 16 added about 3 minutes to my average pace. The pain is in my outer right knee, and I believe it is just runner's knee. I haven't been incorporating strength training, so likely my own fault. My marathon is in 10 days and I've worked really hard. I've been icing and doing stretches to strengthen my quads. Any thoughts on my marathon or additional things I should be doing? Should I not run up to the marathon? I'm on my taper, but have an 8 mile run I'm supposed to do on Saturday. Skip this? Other thoughts? Thank you for your help!