- -By Mike Salamon, Club Julian Trainer
When most people think of cardiovascular exercise, they think of doing at least 30 minutes of continuous, moderate intensity exercise such as walking or using the CrossTrainer. This is also known as steady state aerobics, and at this intensity, the majority of the work is done at the so-called “fat burning zone” and the work is done mostly through the slow twitch or endurance muscle fibers. The main benefit of this type of training is the amount of calories that are burned during the exercise if done for long enough.
But there is another way of doing cardiovascular exercise that involves mixing slow to moderate intensity periods with periods of higher intensity. This is also commonly referred to today as HIIT, or High Intensity Interval Training. Research has shown that this more intense style can lead to greater benefits than with steady state exercise. As the exercise starts to get more intense, the body starts to rely on other fuel sources and uses a higher percentage of fast twitch or explosive type muscle fibers, and this leads to some chemical changes in the body.
Years ago this phenomenon was known as oxygen debt, but now it’s known by the more general term “EPOC” or Excess Post-exercise Oxygen Consumption. An analogy is to picture driving a car on a hot day. After turning the car off, many times you will hear the exhaust fan turn on to help cool the engine down. After finishing high intensity exercise, the body must turn on its own cooling mechanism to restore itself to its original state as well, and it does so by increasing its metabolism which means extra calories being burned for hours after the actual exercise is stopped. 
In my Channel J posts throughout the fall, I will illustrate the many ways to do this with both standard cardiovascular exercises and weights, but the take home message here is that this kind of training can yield the highest benefits when it comes to losing body fat or toning, not to mention it is anything but boring!
It must be said though that this type of protocol isn’t for everyone, and it must be at least modified for those with any medical conditions. Higher level activity depends on the health and age of the individual. It is also important to use this progressively. Generally, a beginner should start with steady state aerobic exercise and progress to mild, low-impact intervals where the more challenging part is just slightly more intense than the easier part.
Stay tuned to Channel J for many specific examples of how to progress and use this effective exercise system!
