Hey guys, this is my first post... I generally like to come and just read, but I have a question that I need answered.
I run at a track about twice a week and perform HIIT training - I sprint for 15 seconds, rest for 23, and repeat 21 times (comes out to be 7 laps around the track). I understand that anything lasting under 30 seconds (correct me if I'm wrong) increases the recruitment of your fast twitch muscle fibers. However, since I'm peforming so many different cycles, will I still be utilizing my fast twitch (IIx and IIa), or would this be considered aerobic and be more geared towards the improvement of the Type I fibers?
Thanks in advance,