Logging exercise calories

luvbwfc

I wear a HRM when doing cardio at the gym. I use the average HR and my weight to get a calori estimate here

http://www.triathlontrainingblog.com/calculators/calories-burned-calculator-based-on-average-heart-rate/

What I am wondering is, should I subtract my BMR for the period fro,m this estimate, the thinking being, that I would have burned those calories anwyay, so they are already included in my daily calorie allowance.

Tried this today, and it only makes an 80 cal diff, so I'm not sure if it is worth bothering with.