I'm learning about this right now and every other day off.. sounds like a good idea.

Some experts claim that 300 minutes of cardio per week is necessary for the over sixty types, less (like 150) for younger, if you can believe that, so I'm backing off my usual 1 hour per day a little and considering 1hour every other day to be about right. I'm averaging about 14mph right now.

I might just take a more leisurely shorter route on days off. Thanks all for the good info here.