I think I'd prefer an orb, actually. 
If anyone is, erm, similarly generously proportioned, with essentially sedentary lifestyle, you might like to tickle your GP for a referral on the 'Fit for Life' scheme. I don't know if it's national (I'm in London) but it's for people who have had, or are at risk of, some kind of cardio-vascular 'event'... Anyway, it involved registering for the scheme (a phone call). followed by a meeting with some fitness person to discuss personal issues (lower back pain etc.) / dates / class choice etc. and then I bought 18 sessions, to be taken over 6 weeks. Gym on Monday and Friday, Pilates on Wednesday. It's all discounted, and our local council leisure centre is really very good. At each gym session there are properly trained instructors, with warm up / stretch down at the beginning / end. As it's scheduled (x time on y day), there is more incentive to get ass out of house IYSWIM.
Anyway, just thought I'd mention it.
The gym also isn't half as bad as I thought it would be. It is still vaguely hellish, but quite fun after a while. The machines have headphone sockets so you can do a brisk walk to some loud boppy music. As I have a WW wiegh in on Thursday, I'm a pretty busy guy, LOL.