The last time a truly gassed myself was about 5 years ago on a climb in Caberfae Ski resort near Cadillac Mi. I was trying to go up as hard as I could and it really is about 1 mile at 6% grade nothing for most but I live in the flatlands of Illinois. The last 400 meters is 9% according to the sign. I got up to the top my heart rate was 162 much higher than it normally every goes. Back then I could sprint and getting about 145 is hard. At the end at the crest I was beat and gasping for air. Not something i am used to doing.

I was primarily a long distance runner of 40 years and could manage in my best year a 39 minute 10K. That would leave me completely spent for the rest of the day and pretty much nothing happening for another 49 hours training wise. The difference then was I was 33 years younger and just went at it. Now at 63 I am much more cautious too many things can happen and go wrong. what might a normal FTP be for someone 60-65 who rides regularly and fit, but not gifted? My guess is about 200.