If you struggling with HR training, the used the PRE scale instead,
1= asleep
2= slow walk
3= slow plod
4= gentle run
5=running and able to hold a conversation
6=exercising and able to string a couple of words together
7=exercising and able to splutter the odd word or 2
8= can manage to say single words
9= almost maxed out, can't utter a word
10=throwing you guts up and giving it your all.