Been working through a mild achilles strain and have been cross-training on a stationary (spin) bike. My easy run pace on the roads gives me an average of about 75% of Max Heart Rate Effort. If I achieve that percentage on the bike while rehabbing, am I doing myself any good? Is 75% on the bike equal to 75% on the road? Today I did 70 minutes with a 42:00 segment at and ave MX HR of 85%. What the Hell does that mean? It was a tough slog for sure.I'm probably a week away from running again. Is this biking crap a waste of time? Am I prolonging the strain (doesn't feel like it...I ice It and do eccentric calf raises multiple times throughout the day. Competitive running is great, but maybe not so much so for folks who are apparently so fragile as I appear to be. Sick and f'n tired of all the injuries.