Rate of Perceived Exertion, and What it Means to You
Rate of what??
It you're asking yourself that question, that's okay. The rate of perceived exertion (or RPE) is a term that fitness professionals use, and probably nobody else. But, if you're going to be working out in a functional fitness gym on a regular basis, you should understand what it means.
Simply put, RPE is how hard you're working. So, when sleeping your RPE is 0. When walking, it's probably a 1 or a 2, and lifting the heaviest deadlift you can is going to be a 10.
The higher on the RPE chart you go, the less time you're going to be able to sustain the exercise. In other words, anything with an RPE of 2-3, you should be able to do for several hours without wearing yourself out. Something with an RPE of 8-9 is most likely not sustainable for more than a few minutes.
If you are familiar with Crossfit workouts, there is an infamous workout called Fran. Fran is 21-15-9 thrusters and pull ups, and the intention is to go as fast as possible. The fittest people in the world can do it under 2 minutes. This is a highly intense workout, and if you're going at full speed, you won't be able to maintain it for longer than a couple of minutes. The RPE should be 8 or 9.