I have broken down a C25K programmer which I have started back doing ... I have no cartilage left in my knees so I have to build up even more slowly in conjunction with faulty intense rehab and conditioning exercises. I managed to get up to about 17mins and then another round of tournaments meant momentum stalled,
I am now thinking to getting a foldable treadmill for the house to make it easier to get some of these done, levels drop a little (I also do the same on a spin bike which is excellent rehab for the knees) and then build up like that.