I was diagnosed yesterday with CHF, so I'm in panic mode right now. I don't know anything about CHF. I understand exercise is recommended. I am (was?) a long-distance bike rider - I usually log 20 miles a day in the winter months and aim for 40 miles a day in the summer. I used to be a marathon runner in my younger days, now I'm 72 years old. I was wondering how much I should shorten my bike rides now. Also - I used to ride at a heart rate of around 140 BPM. I can't believe that would be OK to do now. What heart rate would be recommended? How many miles per day are recommended?