This is a simple way to describe the intensity of your training on a scale of 1 ("Extremely easy", could easily hold this pace and talk for hours) to 10+ ("as fast as you would go if you were running away from T-rex").

0 - Nothing at all

1 - Extremely easy, "could easily hold this pace and talk for hours"

2 - Very easy, "Can talk in complete sentences"

3 - Easy, "Deeper breathing but can speak in broken sentences"

4 - Moderate, "Talking first becomes difficult"

5 - Somewhat hard, "Starting to breathe hard and get uncomfortable"

6 - Moderately hard, "Rapid breathing, talking is avoided"

7 - Hard, "Rapid, forceful breathing and not wanting to talk"

8 - Very hard, "Labored breathing, cannot talk"

9 - Very, very hard, "Starting to gasp for breath, unable to speak"

10 - Extremely hard, "Gasping for air"

10+ - Max, "As hard as you can go, sprint-away-from-danger pace"