The treadmills in puregym have those heart monitor plates on the handles that you can check between sprints where your heart rate is at. I thought they'd be pretty reliable?

I certainly know the sprints I do bring my heart rate to significantly above the recommended safe heart rate for age etc. I bring myself to complete exhaustion every time for someone who is officially very fit as confirmed by the medical professionals who tested my heart whilst on a treadmill.

Would you say the heart rate has to be reduced to a certain point each recovery, no matter how long the recovery period is?