Went out aiming to beat 7300m for 30 mins.....on HM time goes quickly on 30min sprint it doesnt seem to tick down at all...pushed damper up to 6 (from long distance 5) for more power.....really hard work blowing heavy last 10 mins and heart rate hitting 172bpm.... recovery really good though.....hate this sprinting but am not fully flat out cant imagine that would be good