I just received a question from a subscriber of my Wellness Word fitness newsletter regarding safe heart rates when using High Intensity Interval Training or HIIT.
First of all, make sure your heart health has been cleared with your physician prior to engaging in any high intensity cardiovascular workout routine. After that is done, for a quick formula take 220 - Your Age. This equals your maximum heart rate, or approximately how high your heart will beat per minute during intense exercise. Next take 65% - 90% of that number. This will equate to your target heart rate zone. Thus, when training HIIT style keep your heart rate within this range. Of course, the high end will be during your intense intervals while the low number will be during your cool down phase.
This will give you a relatively accurate guide as to what range your heart rate should be in while conducting your own HIIT training sessions. Good luck with your training!