Difference between hard and sub-hard

Explaination on Week 13, session 1.

"Hi Marius
I have a question about week 13, session 1 in the 2:45 schedule. On the left side, it calls for efforts of sub-hard, medium and hard. On the right side, it calls for effort level 3, then level 2, then level 3. What are the proper effort levels for that workout?

I have 3 1/2 weeks left until Boston and am very happy with your plan so far, we'll see how I feel about it after Boston. Your neighbor, Stian Stensland, recommended it to me when he was living here in Fairbanks. I'm 54 and hope to be in low 2:50's at Boston.

Thanks.
Andy Holland"

Answer:Hi Andy and congrats on nearly completing the program. Good to hear that Stian recommends it :)

To your question, I've probably been a bit unclear in the description there. To say it simple, stick to what I say about Effort. So you run Effort 3 then Effort 2 then Effort 3. You may want to push a bit into the very high end of Effort 3 on that last part though, which will put you into the "hard" area.

I wish you all the best for Boston, running those times at your age is a fantastic achievement.

kind regards,
Marius