The Most Efficient Cardio You Can Perform
This is an excerpt from Nick Nilsson’s book Muscle Explosion: 28 Days to Maximum Mass
Interval Training is simply THE most efficient type of cardio you can perform. You can get pretty much ALL the benefits of longer-duration cardio but without the long duration. Moreover, you don’t get the boredom, you don’t spend all your time doing it, and you don’t have nearly the risk of overuse injuries.
In a Nutshell:
Low-intensity exercise is defined as working at a heart rate of about 60 percent to 65 percent of your maximum heart rate (equal to 220 minus your age; thus, if you are 20 years old, 220 minus 20 is 200 maximum heart rate).
High-intensity exercise is defined as working at about 75 percent to 85 percent or more of your maximum heart rate. Using the example of 200 as your maximum heart rate, working at 60 percent of it would be 120 beats per minute. Eighty percent would be 160 beats per minute.