Jenn, kudos on your walk. I have to plump up my veins for bloodwork, too, even when I consistently drink 64 oz. per day. But I do have large veins on top of my hands and it doesn't bother me if they resort to taking blood from there. Wishing you really good results.
Age 67, 5 feet tall
Highest weight ever in the fall of 2010 246 lbs.
FitDay starting weight 1/17/2011 240 lbs.
Weight 3/26/2014 223.4
Current weight 4/4/2014 221.2