vvv sats heart rate during 36 minute run of 5 km ph. does not look great honestly ( if i exert myself). avg heart rate was 154 bpm, and it peaked to 173 bpm towards end of run. it kept on going up and up from time i started run. small dips are during 30-sec walk gaps. i ended my run at 1210am. checked at 1230am and it was down to 104 bpm. infact towards end, garmin watch gave alarm beep regarding heart rate. vo2 max showed no change, ie 44