That's awesome. I have IMTX, IMAZ, and Victoria, Racine, Lake Stevens and Tempe 70.3s this year. Hoping for an Austria roll down in June and my first sub 5 70.3. 35-39 is a hard AG. I hope I have it for another 30 years like you John. Inspirational.
My first sprint was 1 week after 62nd birthday in 2012 after just starting to swim 5 months earlier. Can't run due to bad knees so walk and maybe a bit of jogging. Bike is my passion. Swimming is a bear since I need a total right shoulder joint replacement, told about that 2 years ago, and left wrist replacement needed as of 1 year ago.