Here is a link from the University of Chicago Hospitals on exercise for bariatric patients. It is from 2005 so there is no information on VSG.
I know some people, myself included, have done little exercise in their life.
http://www.uchospitals.edu/pdf/uch_015743.pdf
HW 321 (9/08) SW 312 (1/11) Pre-op 280 (11/1) Surgery 270 (12/11)