target heart rate zone question

jillp0412

i recently got a heart rate monitor and when i exercise i try to stay between 70-80% of my max heart rate, but when i am at this rate i don't really feel like i am working as hard as i could be, not sweating enough, and i have to slow down a little to get back within the range. i was wondering if anyone could explain this, maybe i am not doing the heart rate thing right.
thanks

khrys1

I "think" its supposed to be 220 minus your age..., but I feel like I'm doing a good job if I'm in the 130s or 140s!