50-60% of your Max Heart Rate
This zone is the least intense. You are in it just to warm up or cool down, in order to prevent injury.
60% – 70% of your max heart rate
Stay in this zone if your goal is to lose weight. Your body is fuelled by 10% carbohydrates, 5% protein and 85% fat. This actual number of calories burned per minute will be less than in a higher zone, but you’ll be able to maintain exercise longer
70% – 80% of your Max heart Rate
Also called aerobic zone. In this zone you’ll get the greatest health benefits overall. Your heart and lung capacity will increase and your overall fitness will also increase so you’ll be able to exercise longer. Your body will get 50% of your calories from fat 50% from carbohydrates; protein burn will be minimal.
80% – 90% of your Heart Rate
Also called anaerobic zone. This is a highly intense exercise and should be limited to no more than 10 – 20 minutes. Your body’s ability to consume oxygen will increase. If you push it too hard your body will start producing lactic acid. Your body will burn 85% carbohydrates, 15% fat and minimal percentage of protein.
90% – 100% of your Max Heart Rate
You are pushing your heart to the limits here. And should consult your doctor to check if you can exercise in this zone safely.
Finding Target Heart Rate
The karvonen method factors in resting heart rate (HR rest) to calculate Target Heart Rate (THR), using a range of 50% – 85%.
THR = ((HR max – HR rest) x %intensity) + HR rest
For example, someone with a HRmax of 180 and a HR rest of 79:
50% intensity: ((180-70) x .5) + 70 = 125 bpm
85% intensity: ((180-70) x .85) + 70 = 163 bpm