TR people will probably not like this but I don’t think riding to failure should be done very often except for testing and in races. If you’re constantly pushing yourself hard enough that you have to give up short on an interval, even if that is once per month or every 2-3 weeks I think that is too much.
I just saw a post on another forum about someone who was using TR for 2 years and decided to try something new. He added a long ride per week in zone 2 (3 -4 hours) instead of the tempo or harder ride you would see on a saturday or sunday. Did more tempo work during the week based on HR and lactate vs % of FTP (this will mean you’re truly in tempo), one VO2 workout per week.
**They took their FTP from 270 to 320 and feel fresher day in day out than they ever did performing the TR plans.
I would say you will get more benefit from dropping the intensity period and riding in Zone 2 for an hour than banging your head against the wall killing yourself to hold on to the intervals in the plan.
Added to my original post
On almost every podcast and consistently on TR’s social media you will see them applauding pushing to your limits in training and going for new PR’s etc. Very often I hear “the workouts are designed to be hard but doable”, “use some back pedals or drop your FTP by a few watts until you can just… complete the workout”. I’m a nobody but I completely disagree with this sentiment. What those two quotes are saying is that you basically should push to failure or almost failure on every one of their interval sessions. Some will say that if your FTP is correct they shouldn’t be to failure. I’m referring to what people “hear”. I believe most people hear, “I should just barely be able to complete the workout”.
IMHO this is not a sustainable strategy, leads to mental and physical fatigue, more missed workouts, leaves some people dreading doing the workouts, and doesn’t train the appropriate systems enough. Endurance training is not like weight lifting or other power type sports. You should not be pushing to failure very often. It is about the right balance of training in different zones and then the amount of total volume you can do in the context of your personal life is what will determine how far you can progress. Being fresh to complete the Vo2 or anaerobic session will lead to higher quality work and improvement in those power zones. Performing them fatigued lead to lower quality, lower peak powers for anaerobic work, and high neuromuscular fatigue. Riding harder because you can’t ride longer doesn’t lead to long-term sustainable growth of your aerobic engine.