The RPE scale: 1 to 10
1 - 2
The overall intensity is kept low. Generally, there are no hard efforts included. These are the rides you can switch off and enjoy the day out.
3 - 4
The intensity is lifting, but you're riding within yourself. Even the longer rides can score a 3 - 4 because the intensity is kept relatively low.
5 - 6
The rides are becoming tougher and you need to concentrate on grinding out that extra effort. You may finish the ride, with the legs being slightly sore but you'll be able to back up the next day.
7 - 8
This level of intensity is challenging and not to be underestimated. You're going to feel the fatigue from these sessions, but that will lead to further training development.
9 - 10
You're not coming back from these rides fresh. They are tough but treat it as a challenge. There will be a great level of satisfaction when you complete these!