In the 1960s a man named “Kenneth H. Cooper” came up with the concept of aerobics. Originally, the aerobics points system measured the effectiveness of different exercises and activities for improving cardiovascular health. This led to the term we are more familiar with today known as cardio.
Over time, the main focus of these aerobic-based exercises began shifting from improving cardiovascular health to helping people lose weight and burn fat. It makes sense since cardio exercises do indeed help people lose weight by burning excess calories.
Early science believed that the best way to activate this pathway is by performing long-duration, low-intensity exercises, such as:
- Long-distance jogging
- Cycling
- Swimming
This ultimately led to the creation of other forms of cardio exercises today, such as:
- Aerobic dance classes
- Step aerobics
- Extremely popular Zumba
Although low-intensity cardio is still the exercise king of weight loss and fat burning today. Newcomers have arrived to challenge for the crown! The biggest issue with low-intensity cardio exercises is the duration, which often takes more than an hour.
Cardio may seem to be fun and exciting the first time it’s done, but after a while, it begins to feel way too repetitive and long. As more people become bored and lose interest, more will quit!
Is low-intensity cardio exercise really the best option to burn fat and calories?
The answer: probably not! This is where the most prominent challenger to low-intensity cardio steps in. This challenger is known as high-intensity interval training (HIIT). As the name suggests, it is any training program that is performing intervals at a high intensity while alternating periods of high-intensity activity with periods of low-intensity recovery. The most popular exercise for HIIT is alternating sprinting with walking. Each sprint interval lasts between 5 to 30 seconds and each walk interval will also last between 5 to 30 seconds. The more fit you are, the higher the work to rest ratio will become. For example, if you’re really fit, you might be sprinting for 30 seconds and walking for 10, someone less fit might be only sprinting for 10 seconds and walking for 30. The total session length varies between 5 to 20 minutes and because of the intensity, it should only be done 3 days a week. When added together, that’s a maximum of only 60 minutes of exercise per week!
So what’s the science behind this?
When the body goes through intense activity it needs to be able to keep up with the energy demand. One way it does this is by sending out high levels of fat releasing hormones known as catecholamines, into the bloodstream. The more catecholamines, the more quickly fats are broken down into free fatty acids, which are then used to replenish your energy.
Studies have shown that HIIT also creates this strong EPOC effect. EPOC is short for Excess Post-Exercise Oxygen Consumption. This is the extra oxygen your body needs in order to recover after intense activity. The more oxygen you take in, also means the more calories are being burned. This effect can last up to an amazing 24 hours after a workout!
However, other studies have shown that the number of calories being burned during EPOC isn’t all that much, where at most an extra 60 calories are being burned.
Have you tried high-intensity interval training before? Please share your experience in the comment section below!