Well that's how my mate mainly trained for the half-marathon and his Ironman and he got along fine.(Original post by yoshifumu)
The distances ran would have to be over a few miles, and the recovery barely more than 30 seconds. the number of sets would only have to be about 3-4 if that as well. i know it's possible and has been done, but i don't like very long distance HIIT, i think you could just run continuously and it'd give practically the same benefits.
Mix it up. Do both SSCV and HIIT then. Don't focus on constantly running long-arsed boring distances.
Or does it play no part?