Thank you for posting and for your patience and persistence in restoring your dog's health and well being. About a year ago I saw a man running his GSD pup (about 5-6months) next to him on a bicycle. I tried to catch up to him to tell him to stop, but he was too far ahead.
We also had very nice neighbors that were clueless about dog ownership. They had a Rott mix, huge male about 125lbs. They were in their 50's and decided they should get back in shape. I remember one day the husband came home and was so proud he jogged 5 miles with the young Rotty. After a year the humans looked fabulous but the dog was only 2 and his front legs and shoulders were weak and soar from jogging next to his owners. We used to care for him and he could barely get up into my small low to the ground sedan.