I have been hit by a sudden thought.
I read somewhere (I think Erik Ledin started it) that doing HIIT on lower body days during a cut was BETTER than doing it on off days/upper body days...here is why:
HIIT is basically like a leg workout in itself. Stressing on the CNS, and can be very taxing on the legs. So by combining HIIT with your leg days, you're actually giving your legs MORE rest and recovery throughout the week. Think about it. If you work legs on Monday and Friday (like I do) and do HIIT in between...it's almost like training your legs 4-5 times per week, without giving them much rest. But if you space the sessions, say, a good 6 hours apart (HIIT in the morning, leg training at night) you would actually get MORE recovery, and reduce the risk of over-training your legs.
What do you all think? Feedback on this would be great!