Incorporating Power Endurance Training: Separate Day vs. Within Current Sessions

In many training plans and resources, it's often recommended to schedule power endurance or 4x4s on a separate day from your regular training regimen. This means avoiding combining them with activities like hangboard sessions or lumping them together with power-focused workouts. But why is this the case?

One key aspect to understand is the purpose behind power endurance training. It's designed to help your body adapt to handling lactate buildup effectively. This occurs when your forearms are sufficiently fatigued. The argument goes that by doing these exercises when your muscles are already tired, you're better simulating real climbing conditions and improving your ability to push through fatigue.

So, why is it discouraged to add endurance activities at the end of a current session? Wouldn't pushing through tiredness further enhance adaptation and endurance gains?

As I understand it the reasoning to do power endurance training separate from other training would be that you are trying to train a specific energy system, your anaerobic system, or your ability to sustain maximum effort for longer. If you were to tack on a 4x4 at the end of a climbing session, you are already fatigued and may not have access to that top end power, and so you may not trigger adaptations in that energy system. 

In other words if your top level boulders are v6 you might want to do 4x4s on v4 or v3. If you do a limit bouldering session and work on some v6s and 7s and then try to do a 4x4 you may be so fatigued that you can only do a 4x4 climbing 2s. This would be endurance training sure, but it’s not targeting the desired energy system. This would be “junk mileage”.

Generally speaking the higher intensity stuff wants to be on its own or earlier in the session. 

If you are doing PE training correctly, it is extremely physically taxing. In some cases it can be fine to tack it onto the end of a strength session (e.g., boulderers who are just trying to hang on for a little longer), but as part of a formal training plan, it definitely deserves its own day so you can be fresh for the intense stimulus. 

I think it's fine to do a strength day and a PE day back to back as part of a nonlinear plan and I believe that Bechtel recommends something along those lines. 

Some coaches might worry about an interference effect, where doing a power endurance session after a strength session would lessen the adaptations from the strength session.  I've heard there's evidence for this sort of interference in the strength/hypertrophy world with regard to cardio.

a full on PE workout is somewhat destructive. tacking this on after a full on strength workout would basically be kicking a dead horse.  it will greatly increase your recovery time and just basically dig a deep hole that is hard to get out of.  if you do this consistently you are going to end up injured or just burnt out.  either way your long term performance is going to suffer.