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I know this question has been asked a lot, maybe in different ways, just searching for answers on the internet alone ended up popping up even more questions than answers.

I do a 6 day training program for cutting and fat loss. I do my cardio (treadmill) at the end of my weight training session for 20 minutes.

I am seeing results, but my fear is either I’m not doing my cardio effectively. Either I am doing cardio too hard and losing the calories that are needed for muscle gain from my weight training, or not doing it hard enough and not losing the proper about of body fat.

Using the Karvonen Formula Heart Rate Calculator, 75% of my max heart rate should fall at around 140-144 for a 37 year old, which according to what I’ve seen online and charts at my gym, should be my “fat burning zone” in terms of heart rate.


My question is:

I achieve this heart rate extremely easily with a fast paced walk at about 4 to 4.5 mph, sustained for the entire 20 minute period (able to talk). I do work up a sweat after time, but I do not feel like my body is expending any effort. When I am actually making an effort, let’s say alternating jogging at 7 mph for 7 to 8 minutes (able to talk, but with effort), and walking at 3.5 mph, my heart rate at its maximum is at around 181, and I obviously do feel like I’m making an effort.

I am supposed to feel like nothing is happening for FAT LOSS when hitting my target “fat burning zone”, or am I just wasting my time and should do high intensity cardio? Will I lose the muscle that I’m working on by doing the high intensity cardio?


I appreciate all the feedback you can give me.

Thanks!