Add Yahoo as a preferred source to see more of our stories on Google. Zone 2 cardio rate training means working in one of five heart rate zones at 60-70% of your max heart rate. "Zone 2 is where the ...

This secret to improving your cardiovascular health and endurance: zone 2 heart rate training. Zone 2 cardio rate training means working in one of five heart rate zones at 60-70% of your max heart ...