How to calculate exercise calories?

Mateo1985

Hello guys,

I was wondering if somebody could help me out with an advise. I'm currently going to a MMA gym. I usually spend about 3 hours a day there 5 times a week. Really sweat a lot so I'm sure I'm actually going through some good workouts there. Classes consist of Kickboxing, Jiu Jitsu, Muay Thai, Grappling, Conditioning, Punching bags etc. I wanna be eating my exercise calories back on the days when I go to the gym so my muscles have enough materials to develop and heal but I'm not sure how many calories I'm using for the workouts. Is there a way to count without using a heart rate monitor? Or should I actually invest in one?

Thanks a lot for the input guys