Not much out there on calories per arrow, which is what I was after.

Only found one on physics where they calculated 2 calories in total for 72 arrows for a 40lb bow. That seems very low to me.

Should be easy to work out:

Force X distance = energy

40lb peak weight is about 20lb average.

28 inch draw from an 8 inch brace height is 18.25 inches.

Put that into units it's possible to work with...

90N x 0.45m = 42J

Efficiency is tricky, but you're looking at 40% for purely aerobic, down to below 10% for weight lifting, so let's call it 20%.

Giving us 200J for a single draw.

That's 0.05kcal per shot, 3.6kcal for 72.

Of course, you're burning energy holding at full draw, so you'd need to add on a bit for that, plus the mile you walk to and from the target, pulling arrows, standing around, talking, trying to find batteries for the metal detector, etc, etc.