The general concensus seems to be that HIIT is an exellent way to burn fat in a cutting phase. But does HIIT cardio training burn more muscle that a steady 60 to 70% BPM? Currently, I am using a variation of HIIT for 1 hour in the morning and 1 hour in the evening. I do 9 min @ 65% and 1 min maxed out @ 95 to 98%. then repeat. It seems like my heart rate stays above 70%, 30 minutes out of the hour. In an aggressive fat cutting phase, I'm losing on average 3 lbs of fat per week, but I am also losing about .5 lbs of muscle. Please assume diet and weight training to be dialed in. Maybe slow and steady would protect more muscle?
Your thoughts are appreciated as always!