When creating custom exercises, having a reps x seconds option for interval training. Reason being, is I am currently unable to use the progression spreadsheet for programming different progressions of conditioning/interval training and the only work around I have found is to create the conditioning exercise as though it's a strength exercise (reps x weight) and explain in the notes that the weight is seconds, which can cause confusion for some clients. This is the only way I can change both the number of seconds an interval is and the number of reps to do in the progression spreadsheet without duplicating and recreating the entire session.