The main benefit is getting a much more accurate picture of how many calories you truly burn throughout the day. Heart rate monitors only work accurately for estimating calorie burn when you are actually exercising intensely. They become much less accurate when you are doing light activity or are at rest because the algorithms they use to estimate calorie burn rely on actively working large muscle groups. If you read the manual to your heart rate monitor (if you have one) it will say something along those lines.
Sites like Sparkpeople try to do a decent job at estimating your basal metabolic rate based on your age, weight, height, and "activity level", but the truth is some days you are more active than others. Yesterday I burned over 3000 calories because, not only was it a cardio day, but I was running all over the place doing errands and such. Today was a cardio day too, but I'll be lucky to hit 2600 calories burnt, because I spent most of the day laying on the couch watching TV. Sparkpeople would have guessed roughly the same calorie burn for both days!
You get a much more accurate idea of how the little things you do throughout the day add up and contribute to your total calorie burn.
| current weight: 202.2