Does heartrate increase during the last part of the menstrual cycle? I was doing a test for VO2 max, and my heartrate went much higher than it usually does when I was exercising (it was a step test), and my resting heartrate was 84 (normal for me is about 70). I am wondering if the stage I am at in my cycle might be affecting it, and if it is better to reschedule during my period?