something I wrote to someone (cyclist) today:
12:53 <@irma> some research warns against 30's RHR ... but, I wonder if there's a difference in how it's achieved.. ie, achieving it by being very lean & light, with low/moderate cardio, versus: TONS AND TONS AND TONS OF CARDIO
12:54 <@irma> the former seems safer ... your heart just doesn't have to work as hard, not as much mass/tissue to pump blood to
12:54 <@irma> the latter is an adaptation to very high levels of cardiovascular work
12:56 <@irma> i mean you hear stories of some people requiring pace makers later on in life.. like alberto salazar
12:56 <@irma> but, i wonder if that's also partly due to drug use in addition to tons of mileage
12:57 <@irma> i don't want to need a pace maker later on in life, that's for sure