I have to admit for the past few years I had gotten somewhat lazy and used my age as an excuse not to push myself through the pain barrier. I kept telling myself "at my age I just need to maintain, no need to kill myself" and was just going through the motions for the most part. But after deciding to compete again and training with the guys in Aruba, I have found that zone again. Maybe it's because I now have a reason or a goal I want to reach, whatever the reason I am now training in the 4 zone and sometimes hitting 5, especially on leg days.
I have been sore as hell and have had days I had a hard time walking but damn does it feel GOOD!