Trim Stab,
I would suggest that you are talking about something you know nothing about (excusable to a certain extent as most people on this forum do the same), and are making gross assumptions. Take one look at the images here:
https://www.google.co.uk/search?q=DI...w=1241&bih=606
....and tell me that
all the people involved are "relatively mobile and fit"!
