Good for you guys!! I already took care of being out of shape last year... had an extended layoff from regular exercise for multiple reasons. Everything is back on track with a minimum of 3-5 hours of training per week. Having good conditioning (in my mind) is pretty much a necessity with carrying heavier gear and extended hikes in the field. It wasn't difficult to get back into the groove and get into shape after that, due to previous background in sports/competition.
During the wildlife photo competition last year, on one trip I dropped 4 pounds in 8 days. I was eating only 1500 calories/day, since you don't want to leave the blind too much and disturb the target areas. Lots of fluids though, so it was real weight loss...
Regards,
Marc