Well you certainly won't need anything using energy system training like HIIT unless you've already dieted down significantly. There's been so many people who have relied on low intensity steady state during their off days and got shredded that it's rediculous. It's simply not needed. Especially IF you're lifting as heavy as possible. I'll go on the treadmill at a 3.5 speed and a 3.5 incline for 45 minutes done deal. A good rule of thumb is a heartrate of 130-140 bpm. You're just burning calories here.
Now, if your fatloss starts to slow on progress, or you feel there's some benefit to using HIIT, then by all means. But if that's the case, you're going to have to have more carbs in your day to day diet vs. low carb or keto since the high intensity interval training will be running off of carbs for energy.
So you ask yourself - As I'm continually training as heavy as possible, what will enable me to make the most consistant strength gains while in fat loss mode? Almost always to least invasive approach always wins. There's a reason why we don't do HIIT while DC training - Ever.
I wrote an article at IA's forum:
http://ironaddicts.com/forums/showth...178#post276178