Recovery Ride

Somewhere I read that a real recovery ride is so slow that you have to take a different route so that your friends don't see how slow you are riding. Friday, I tried doing a recovery ride keeping my heart rate below 70% of max. This was easy on flat road where it meant keeping my speed at about 15 MPH. The trouble came when I hit a hill (like an overpass, I live in the flat lands), I had to climb at about 7-8 MPH to keep my heart rate low enough. Now I understand why one might want to take a secret route.