My actual aerobic threshold is 152 beats per minute in ... So today, let’s look at one simple way to calculate your heart rate zones to help you calibrate your training intensity.

One common method is to determine your maximum heart rate (220 minus your age), then calculate 60 to 70 percent of that number—that’s your aerobic threshold, the very top of your Zone 2 range.

You create more ATP as you exercise, and which type of fuel your body uses is determined by which heart-rate zone ... pyramid is your aerobic energy system and is where zone 2 sits.