HI. I got to week 8, and I knew 28 minutes was going to be a bit tough, but I seem to be struggling more than I expected. I seem to be way shorter of breath than I was in week 7, and my joints are complaining a lot between runs, hips and knees mostly. Leg muscles are fine, just the normal achiness that I'd expect from doing a workout. I think perhaps i'll step back a few weeks and stay at that level till my joints settle back down, and work up more slowly.