Looking for suggestions to changing up my training

So i am an old dude. I bought a trainer wahoo core to help with my overall fitness.
i have done 3 consecutive 6 week ftp builder training programs since i bought the trainer and was feeling pretty good.

Today is the first time i went outside to ride. On some good climbs the legs were great but the lungs were toast. So i must be doing something wrong in my training.

Would love to hear any suggestions on what i may change to help improve.


How long was your outdoor ride relative to your indoor rides? The ftp builder program doesn’t really focus on aerobic capacity.

Try a Google search for “cycling aerobic base training.”

hi jim, thanks for replying.
my indoor rides are normally 60 - 80 minutes. today outside ride was 30 maybe even less. had to climb a big hill first. Thanks for the google key words . will try that

Is your indoor cadence about the same as your outdoor cadence? Did you do an FTP test after each training plan completition?