Maureen.... What ever speed is good for you as a beginner is the speed for you, only YOU can tell... If your heart rate was at 161 and your were feeling ok, not completely breathless, nauseus or dizzy and could still keep up a decent conversation, I think you were ok... The monitors on the machines are inaccurate, I wouldn't rely on them all that much...
Today I did some HIIT on the
and a very quick chest workout...