question about bpm during cardio

[BIGMAC250]

how beneficial would it be to get a heart rate monitor. how important is heart rate during cardio? is it something that can make a huge difference in how much i lose? sorry if its a dumb question but ive never payed too much attention to the little details like that. i want to make sure im doing everything possible to get rid of the excess adipose....all input is greatly appreciated.

[Twist]

very important. also during workout not just cardio. rest between sets at a certain hr. I am 22 so I rest at 100-105 bpm for 1minute