OR REPS IN RESERVE SCALE
Next, I’m going to introduce a chart that represents a scale you will use to monitor your efforts during physical activity, called the Rate of Perceived Exertion (RPE) or Reps in Reserve (RIR) if you are lifting weights.
With lifting, I prefer the RIR scale because it’s SLIGHTLY more objective. I find that often, it’s easy to say something was “hard”, but when asked to do as many as possible people can sometimes do a whole other set before truly getting to FAILURE.
Every set should absolutely not be to failure, but to be aware of how hard you’re actually pushing by every so often hitting failure is not a bad thing. The majority of your sets should reach an RPE OF 8-9 with 1-3 RIR at the very most. Anything less than that is cheating yourself and slowing progress unless it’s a deload week.