Dont do it Joe, I have a back problem that earned me a blue parking badge, I just dont put quite so much fuel in. Joking aside, after an mri scan last year the doctor said my back joints are arthritic and are the back of a much older person, he said I should give up jogging and avoid heavy lifting. I am a tv engineer with paramotoring and jogging as my main hobbies - aint that a bitch! On the other hand another back specialist said my back problems only showed up as a result of a routine scan to check a slipped disc and that lots of people have similar problems but dont know it.