Peak 8 Training - Anyone got any stories

I've been on Peak8 for over a year. I'm 58, so my calculated max heart rate is 162 (220 - your age). I have a Garmin Forerunner 305 that I wear to track the workout. I generally hit at least 160 and usually use an elliptical machine. I was doing one every 3rd or 4th day, twice a week. I'm 6'3" and started about 225 lbs. Today I weighed in at 194. For the past 10 days I've been doing one every 48 hours and have fasted for at least 2 hours after to maximize HGH production. It hasn't seemed to have impacted my max heart rate with the increased frequency. My best was in December when I hit 170. I've been tweaking the elliptical settings and backing off the maximum tension. The max setting is 20 and I'm doing my 30 second sets at 15, then back off to 4 for 90 seconds.