Actually, the blast-only premix is the only way I do I-Max 3; I like to kick things off with the I-Max 1 warm-up, then HSTA cardio-only premix, I-Max 3 blast-only premix, Kick Max blast challenge, and Boot Camp cardio-only premix at the end. Did it just yesterday.
I always cringe a bit when it gets to the dreaded Interval 5 (The Plie Jacks From Hell), but after I polish that one off I know I'm good for the rest of the premix.
A-Jock