I think: is this a situation (interval, whole ride, etc) where I would WANT lactate to go up or NOT WANT lactate to go up. In training, there sessions where low lactate is what you’re after, and others where you’re trying to increase it.
On 30 min tempo intervals, I don’t want lactate to increase in a meaningful way; therefore don’t want to see significant amount of decoupling during the interval.
On the other hand, I would expect to see decoupling in the last intervals of a classic VO2max session, or Supra threshold intervals where you went long enough to be at VO2max.
Over unders. lactate up, then clear it (with certain types of O/U).
A variable intensity group ride: decoupling metric mostly meaningless (too many confounding variables)
Agreed, it’s a useful metric for determining aerobic conditioning.
A metric based on Power:HR rate of acceleration/stabilization after the onset of work would be useful. Even for shorter intervals, as the rate of acceleration would give insight into aerobic fitness (i.e., if the O2 debt is being covered by glycolysis or not).
I see what you’re getting at now and yeah, it might be an interesting/useful metric. I have had two coaches in last 4 years and whereas both looked at decoupling by manual inspection during high intensity work, not just for low intensity work (the point I was trying to make above), neither used any sort of rate of acceleration or decay.