220-age = max
, the target is 70 to 80% of ur maximum heart rate
, which is 220-ur age (e.
g., a 40 yr old has a theoretical max HR of 180 bpm, & 80% of that is 144 bpm). Anything above the max is not healthy if u r not used to exercising. 15 min after exercise (complete rest), ur HR should drop back down to less than 100 bpm. Anything above that means something's not healthy. TTYD or cardiologist