Exercise... Eating back the cals/points/syns

So I guess this applies to many people here.... I'm personally calorie counting but it was a question when I did weight watchers too.
When exercising I burn a fair wack of calories.... According to my fitness pal I can eat them in addition to my daily calorie allowance....
But should I?
What does everyone else do?

I don't personally - plus I have never totally believed the accuracy of calorie burn estimators even the HRM I had...

That said, if I am feeling weak before/during exercise or ridiculously ravenous after I will have a little something extra or perhaps increase my portion for dinner. I think listen to your body and don't eat them back for the sake of it. I found I got into the habit of going to several gym classes or on a run and seeing 400 or so "burnt" on my HRM and thinking that meant a bar of choc or icecream almost every day would do no harm!