PAlt

I use a Polar S725x. I am trying to build my endurance & climbing strength, am using zone training to help build base miles (Z1 & 2), as well as doings intervals and spinning and climbing drills to build strength (upper Z3 to Z5). Had an exercise physiologist tell me that at age 50 & above, our bodies want to lose muscle mass, relative to younger folks, so it's important to build or keep muscle. Also told me that since I'd lost weight, and he estimated I was generally riding in Z3 during my rides, that I was neither building muscle nor building endurance, just sort of "static". Since these are goals for me, the HRM was and is a good investment.