Gauging RPE on time-based exercises?

[physiatry111]

Hi,

How should I gauge RPE on time based exercises, e.g. planks and wall sits? Is it purely subjective or is there some kind of reps in reserve equivalent?

[Jordan Feigenbaum]

It'll be more of a proximity to failure or level of exertion rating vs a true "reps in reserve", but it can work

I'd do something like this:

RPE 6- relatively easy effort that is more boring than hard. Difficult to predict time to failure from this level of exertion.
RPE 7- moderate effort that is somewhat challenging, but sustainable. Predict failure within 90-120 seconds.
RPE 8- hard effort. Predict failure within one minute.
RPE 9- very hard effort. Predict failure within 30 seconds.
RPE 10- maximal effort. Failure is imminent or actually to failure.

[physiatry111]

thanks Jordan.