Okay, I'm not sure what you mean here. You're mixing "train" and "race" in the same paragraph, and I'm really unclear about what you're talking about.

Also, for your 12 km "spirits" (?), you do HIIT? I can only manage HIIT for about 5-8 minutes before throwing up, and I'm in REALLY good shape. How on earth do you manage to do HIIT for 12 km?

Or do you mean Interval Training?