Originally Posted by PeteHski

Neal Henderson (Wahoo fitness coach) said that you needed a minimum of 15 hours per week of low intensity training to see any significant advantage compared to a more balanced intensity, relatively low volume plan.

Being cynical you could just say that he was promoting Wahoo training plans. But I think he was just being realistic about the training volume available to most amateur cyclists and what is actually likely to be the best bang for their buck. Anecdotally, I know a few older riders who do 10+ hours of riding per week at moderate intensity and deliberately avoid higher intensity intervals. They are all relatively slow and struggle to deal with changes in pace when riding in a fast group. I seem to cope better despite often training on a sub 10 hour plan. This year in particular my volume is down to as little as 5 hours per week and yet I still feel strong on tough century group rides.

The key seems to be a measured dose of VO2 max intervals along with a couple of 2 hour Z2 rides and maybe the odd 1 hour sweetspot session. I find this to be pretty efficient when I don’t have any more time available to ride.