RPE 1-2 Very easy – you can converse w/ no effort
RPE 3 Easy – you can converse w/ almost no effort
RPE 4 Moderately easy – you can converse comfortably
RPE 5 Moderate – conversation requires some effort
RPE 6 Moderately hard – conversation requires a lot of effort
RPE 7 Difficult – conversation is challenging
RPE 8 Very difficult – conversation is very difficult
RPE 9-10 Maximum effort – basically no talking