Ideal Target Heart Rate for Max Fat Burn While Maintaining Max Muscle?

[ascendant]

Years back, I was used to most sources saying the ideal range for maximum fat burning with minimal muscle loss is 60-70% of your max HR. When I search the web now, most sources are saying 70-80% is the ideal range. My understanding has been if you push too hard with cardio, your body will start to tap into muscle and make it a lot harder to maintain your muscle mass while cutting up.

Yes, I'm well aware that more intense cardio burns more fat, but I'm trying to minimize muscle loss. All the pros I used to learn from back in the day always did pretty low intensity cardio for longer to keep from losing muscle while cutting up. I'm really hoping to keep the muscle mass I have while cutting, and then just maintain from there on out. So, figured I would get feedback on here, as I find it much more reliable than mainstream info.

[Marsoc]

I do massive amounts of triple drop sets and even a super set attached at the end (all considered 1 set) for about 4 sets each of whatever I do. I only rest 35 seconds between each set so it’s cardio in a sense. Never thought about heart rate and don’t care to, just go all out to failure and break thresholds to grow.

[Painjunky]

You need to do some sort of assessment to get your proper hr zones. Everyone is different. Once you have them,
Stick to zone two for fat burn. Anything higher and you start to burn glucose for fuel. That doesn’t mean you can’t go over when in the gym but definitely no more than zone 2 for your long cardio sessions. That would be optimal to burn fat for fuel.