Originally Posted by
GhostRider62
OP is 70 years old. He rides 2-3 time per week for 25-30 miles and you want him to be doing HIIT? Jump right into a 50-60 miler on the weekend? To train for a Century? Why? Are you trying to kill him? Or just train his metabolism in the completely wrong direction for a 7-8 hour century, so he can bonk sooner?
OP is not a racer, a sportif rider, or even a randonneur. He merely lacks the endurance to comfortably ride a century and that is accomplished with building an aerobic base, which emphasises type1 slowtwitch muscles with just a little bit of anaerobic work. He does not need 5 minute VO2 max to bridge up from the team car.
That's not what I meant at all. Maybe I wasn't clear, but I was merely suggesting he does a couple of shorter, higher intensity rides during the week (doesn't have to be full-on HIIT) and a longer, low intensity weekend ride building up to the higher mileage ready for a century. Rather than the OP's idea of doing 6x 1 hour high intensity sessions (which may well kill him!)
Last year he stated that he was riding 3x 2 hr sessions (6 hours total) and I'm suggesting he rides 2x1 hour plus 1x 4 hour (6 hours total). Of course the longer ride may need to start off shorter, but I'm not writing his detailed training plan here. Haven't even mentioned recovery weeks etc. e.g. 2/1 build recovery cycles.