My knowledge is also limited. Judging by how you feel, you are probably hitting or getting very close to your max HR. My understanding is that max HR does not actually change, however, with training, the amount of effort you can exert without hitting your max is what increases. By backing off before your reach max, and by specifically training to more like 85% a lot, you should find that efforts that once caused you to max will eventually not.

The time it takes for your HR to come back down to normal is the recovery time. Apparently, interval training is the best way to train your heart to recover faster.

I haven't worn my HRM for the types of exercises that you are indicating, but I have found that spinning on the trainer, my best recovery happens with lighter faster spinning, not by stopping.

Tonight I'll be doing a test to find my lactic balance point - the point where I produce lactic acid and remove it at the same rate. After I know this, I'll train 80% of the time at or below that rate and 20% of the time above it. I'm hoping this will take some of the mystery out of my heart rate!

Hugs and butterflies,
~T~