Originally Posted by
bobwysiwyg
Thanks, I understand there are better ways, but really my point was how, if at all, might an abnormally low resting rate have any affect on the thresholds of other heart rate zones.
Not really. It would affect your zones if they're based on Heart Rate Reserve, which is defined as the range from your resting HR to your max HR. In that case you should really know your true max HR, because with somebody who has a really low resting HR, their max HR is
probably lower than average also. In that case using 220-age could throw things off.
IMHO the threshold-based zones (using Friel's 30-min test to determine threshold HR) are the most useful. Partly because people are more likely to end up with accurate zones based on threshold HR rather than trying to determine max HR. But also because threshold-based HR zones will scale with fitness. As you get more fit, your threshold HR will tend to go up (to a certain point, there will still be a ceiling). So having HR zones based on your current fitness level is more useful (just like using FTP to determine training zones with power meters).