so i joined the ymca today, i was on the stationary bike, and it said my heart rate was a steady 185-190. and it said my max heart rate would be 220-25(my age)=195. so i figured maybe id try and do some hiit, but my heart rate wouldnt fluxuate quickly enough to do hiit like i have read about, so i kinda just pedaled real fast for 30 sec. then slowed it down a bit for 30 sec. for a couple min. my heartrate stayed pretty steady, but i thought that was how you were supposed to judge your hiit.