Ok. Other than my Zpacks tent which should arrive in mid August, I am about ready for my first short trip on the Appalachian Trail. I was not aware of the expense of getting ready. I have also been training by walking on a treadmill at a 15° incline at 2 1/2 to 3 mph. now my knees are starting to ache. I would hate to think I will begin my initial 42 mile hike, and find that my knees hurt too much. Is this common? I am 56 years old. Is there something I can do to help the ache in my knees? I would hate to think I put the cart before the horse and purchased everything I needed only to find out I cannot make the hike.