Sawing Wood

im new to MyFit essPal and would appreciate some advice about how to enter strength exercise

I'm regularly sawing wood for say 15-30 minutes at a time. A web site I've tracked down suggests that sawing wood for
10 mins uses 54 calories
30 mins uses 161 calories
60 mins uses 322 calories
And that's based on someone weighing 65kg or 10st 3lbs (I'm 14 stone) but using these figures how would I fill in the required fields when adding a new exercise