High Intensity Interval Training

There is a new trend going out there saying that High Intensity Interval Training is the best option if you want to lose weight and get in shape, and that aerobic exercise is not that useful. First like always let’s clear up the difference between one and the other.

1. High Intensity Interval Training (HIIT) - I will use the definition given by Wikipedia, since it’s pretty accurate: HIIT is an exercise strategy alternating periods of short intense anaerobic exercise with less-intense recovery periods. HIIT is a form of cardiovascular exercise. Usual HIIT sessions may vary from 4–30 minutes. These short, intense workouts provide improved athletic capacity and condition, improved glucose metabolism, and improved fat burning.

So basically the whole idea of using HIIT is to raise your heart rate and then allow it to come back down again. One example of this would be for example sprints. The person runs as fast as they can for 15 to 60 seconds, then stops, rests for 30 seconds (or until their heart rate reaches 60% of their capacity) and then does it again. They could do this for 3 series or more and that would be an example of training with HIIT (I highly recommend to train with a watch that measures your heart rate when training with HIIT).

  2.   Aerobic exercise. It’s light to moderate intense activities, and refers to the use of oxygen to meet energy demands. Running 5 km is an example of an aerobic exercise.

OK, now that we know what both things are, let’s see the benefits and risks of HIIT activity.

Benefits of HIIT.

1. A study published in the International Journal Sport Nutrition and Exercise Metabolism found that 2 minutes of intensive sprint interval training perform 3 times a week, during 6 weeks, was as good as running as 30 minutes, 3 times a week, during 6 weeks. So we can say it’s more effective for people who have less time to work-out.

2. Increases Aerobic capacity. This may seem strange to people, because when you are training HIIT you are actually doing Anaerobic, but different studies have shown that it also increases the aerobic capacity.

3. Increases Insulin sensitivity. This could be confusing to people so let me clear up what insulin sensitivity means: Insulin sensitivity describes how sensitive the body is to the effects of insulin. Someone said to be insulin sensitive will require smaller amounts of insulin to lower blood glucose levels than someone who has low sensitivity. Insulin sensitivity varies from person to person and doctors can perform tests to determine how sensitive an individual is to insulin. So the more insulin sensitive you are, the less likely you will develop type 2 diabetes. HIIT causes your muscles to absorb glucose more readily, preventing it from being stored as fat.

4. Improves fat burning. It has been proven that the higher the intensity is during your cardio the more calories you will continue to burn after the exercise!!    

Risk of High Intensity Interval Training

1. I think the greatest risk is that you probably have a higher probability of getting injured. I haven’t read any articles that say so, but that is my conclusion. The higher the intensity of the exercise, the more likely you will get injured.

2. You have to be in shape to do this kind of exercises. HIIT is not for everyone, especially people that are just starting to do sports. With HIIT your heart level reaches sometimes 90% or higher of your capacity. So I really don’t recommend this to any beginners.

Seeing the information we can see that HIIT is quite effective and probably can help you a lot in getting you in shape. HIIT will probably also help you get better physically at whatever sport you are practicing but the important thing to have in mind is that you first need a base to be able to do HIIT, and this base will only be acquired through aerobic exercise.

Having said that, I think a combination of both activities is the best option for most people. Aerobic activities have been proven to produce great effects on the body and mind of most people, but if you want to train a little harder and obtain better results you should try to “slowly” begin with HIIT.

My next blog will be about the topic or myth that exist out there, that low intense cardiovascular exercise will burn more fat than high intense cardiovascular activities. We will see if this is true and the explanation behind it. Until next time.