Correction male HR is 205-half age from what I've learnt at uni
That's a general guideline. I believe that's your target heart rate, a zone that allows you maximim conditioning, and a rate that you shoukd be able to maintain for a period of time. Years ago, I was a highly trained amateur athlete, and I could get my heart rate above 200 during "full smoke" sprints of short duration. So I wouldn't let that guideline influence you. But I would add that the return to normal respiration shouuld be a ramp down process. If your breathing return slows, but your heart rate is still banging away, then that should be something that you'd want to have looked at.