I used to cycle a lot last year but to be honest I've been pretty lazy this year so far. That was until this week when I said to myself I'll spend the next month building up my fitness. I'm 26 years old. I've started a routine of 16 miles a day over part hilly, part flat terrain which I've done since Monday last. This usually takes me about 1 hour 15 mins and my heartrate averages 165. My Resting heartrate is about 65 and my max is about 200 I'd like to do the 6 days a week for the next month to build back up my fitness level (and shed a few pounds in the process) but I was wondering would this be overdoing it. I have no heart problems but I read that you shouldn't go over 80% of your max heart rate while doing cardio, thing is I feel really comfortable training at 165 HR which is 83-84% my max rate, any less and I feel like im not pushing it at all. Any advice would be great.