Make sure the dog is in good shape and build up his endurance over time.Now I'll tell you the rest of the story.Took my dog on runs for 2 weeks.Over time Casey had a hard time getting up.Brought him to the Vet.The Vet asked if Casey was doing anything different from his routine.Oh boy, Vet scolded me for being so stupid as to take the dog on runs that he wasn't prepared for.Went back to walking him legs returned to normal.