HIIT and heavy lifting?

Sam_I_Am77

Remember that the purpose of a warm-up it to get the blood flowing and quite literally, warm-up your soft tissue. The cardio should be light especially if you're truly going heavy. Remember that HIIT and Maximal strength training (aka heavy lifting) are competing for the same energy system (anerobic / ATP) so they don't exactly compliment each other in that regard. Leave the HIIT for after or on an non-lifting day.