Running time again.
Any – literally any – interval is a good interval.
What matters is rest. You can do same rest, half rest, or double rest. You probably want to start with double rest so, obviously, whatever your interval was you rest for twice that long.
And the shorter the interval the harder you want to run. Like, if you’re doing 2 minutes it’ll be a 7 out of 10 on the effort scale, if it’s 30 seconds – go 10 out of 10.
You should be running twice a week at this point. One longer, slower run and one interval session.
It’s important to remember that running (and getting wet I guess) is the one thing you can’t avoid at Spartan. Anything else you can fail and do burpees but it’s not like you’re going to walk the whole course. It would take forever. And I’d fucking disown you.
So it’s the tenth commandment of Spartan training – thou shall run.