What Is High-Intensity Interval Training?

There is always a battle in the fitness community between high intensity exercise an steady state aerobic exercise. I don't know why some experts like to operate on one side of the fence or the other but it is common to hear that one form of cardio is better than the other. But the truth is you need both of them. There is room for both of them in your training programs.

High intensity interval training (HIIT) is when you alternate between high and low intensity exercises or between high intensity exercise and a short period of rest. For example, a short sprint up a flight of stairs followed by a walk back down is interval training. Or a sprint on a treadmill followed by stepping to the side and resting for a short period.

High-intensity aerobic interval training (HIIT) is a popular strategy for improving cardiorespiratory fitness and health, as well as reducing body fat levels. High-intensity intervals are typically performed above the lactate threshold. You know that crazy burn feeling you get when you are gasping for air after running up a big flight of stairs? The science of that feeling is called lactate threshold. This high-intensity bout is then followed by a low-intensity recovery period that allows the body to buffer and clear lactic acid from the blood, thereby allowing the individual enough time to recover and perform another high-intensity interval.

Most every high intensity physical activity is a state of “crisis” in the body. It endangers oxygen supply to tissues, increases body temperature, reduces body fluids and fuel stores, and causes tissue damage.

HIIT has been shown to improve cardiovascular function and stimulate greater weight loss compared with traditional steady state aerobic training. I believe there should be a great amount of caution exercised when using it if you are a beginner. It is very important that you should establish some type of aerobic foundation before you attempt to try HIIT protocols.

I will cover what an aerobic base is in detail on a later post but I want to give you some context now as well. The more work you perform aerobically, the more efficient you are. Aerobic training produces muscular adaptations that improve oxygen transport to the muscles, reduces the rate of lactate formation, and improves the rate of lactate removal and increases energy production and utilization. These adaptations occur slowly over time.

As a result of that adaptation, you will become more efficient at HIIT training programs. HIIT can be a time efficient means to improve cardiorespiratory fitness and reduce body fat levels over and above what is possible through steady-state aerobic training. But if HIIT is done to much it can be associated with an increased potential for overtraining, especially when combined with regimented resistance training.

It is essential to understand that balance is important. It is great to integrate HIIT training in your program but do it in spurts and not as your training program as a whole.