Hi,
Sounds like you're doing well and glad you feel well enough to want to start exercising again.
My boyfriend will be a year post Whipple on 9/7/08 and has started back running and lifting some light weights in the past 3 or 4 months. Before he got sick he was running 5+ miles a day and lifting weights and when he started back he was trying to do too much too soon and had some stomach problems, but then he cut back and started "slowly" working his way up to it again and seems to be doing fine so far.
They told him at M D Anderson that he needed to take calcium supplements for bone density and that he should exercise, but start off slowly and work his way back into the exercise mode. PanCan ( www.pancan.org) may have some guidelines. You can call and speak to a PALS Associate, 1-877-262-7226. They may have some information to send you about it also.
Also you might go ask people on the Johns Hopkins PC Chat Board about it.
http://pathology.jhu.edu/pancreas_chat/ Good luck and stay strong.
Donna C in FL