The fitness world is chock full of “miracles” and “six-pack abs in a week”, so much that new workouts and exercises are met with widespread skepticism concerning their effectiveness and safety. But when it comes to High-Intensity Interval Training (HIIT), the benefits are indeed legitimate and – dare I say it – miraculous.
High-intensity interval training is when you alternate between periods of high and low-intensity exercises or between high-intensity exercise (85% or higher of maximum heart rate) and a short rest interval. The theory behind the exercise is that short, explosive exercises allow you to engage your heart much better than you could with steady-state exercise, thereby burning more fuel and fat. HIIT can help lower your blood sugar levels and reduce abdominal fat, thereby lowering your risk of developing insulin resistance or Type 2 diabetes, and other cardiovascular diseases. Typically, the high-intensity exercise lasts from 15 seconds to 4 minutes and approach 80% to 95% of an individual’s maximum heart rate. Recovery intervals generally consist of passive rest or mild activity at 40% to 50% of the maximum heart rate. The combined work/rest interval generally is repeated 6 to 10 times.
In order to accurately implement HIIT, it is important to define the basic variables associated with HIIT:-
- Rest periods
The intensity of the training depends on your personal limits – how intensely you can work out, how long you can practice HIIT in a session. There are several ways to practice HIIT; sprinting, cycling and rope jumping are some of the most common HIIT exercises. Let’s go over the different stages of HIIT and review their effects on our body. The most basic HIIT is sprinting full speed for about 30 secs, followed by a rest interval.
Stage 1 – During the first 10 – 20 secs, our body tries to adapt to the high-stress situation and responds by releasing phosphocreatine, a high-intensity energy source.
Stage 2 – Nearing 20 secs, our phosphocreatine reserves start to run low and due to the limited supply of oxygen, anaerobic glycolysis takes place. This process further supplies 30 secs worth of energy, on an average. However, our muscles start to burn due to the lactic acid produced and the high-speed sprint starts to slow down.
The objective is to go all out during a session, get that heart rate up so that, due to insufficient energy reserves, the body is forced to burn fat. As Nietzsche gasped during a 20-rep squat set, “That which does not kill me makes my quads bodacious.”
As with every workout, HIIT demands proper diet, regular pre- and post- workout practices. Pre-workout practices are a must for HIIT, which is much more rigorous than most exercises. Proper hydration and a short warm-up will go a long way in ensuring your body is eased into the HIIT and not shocked into it. Post workout replenishment will save you from the blackout (dizziness), which results from expending too much energy.
However, HIIT is not all sunshine and rainbows, as some would lead you to believe. Despite its many benefits, HIIT does have its disadvantages, the common ones being:-
- Relatively high injury risk
- Long recovery period
- Not suitable for beginners
- Incredibly taxing
That said, don’t overlook this form of exercise. It has some really great upsides:-
- Increases metabolism
- Burns more fat than normal exercises
- Increases cardiovascular health
Expert tip: Don’t put much stock in scientific results and studies – they’re only accurate to a certain extent. Many tests fail to take the subjects’ diet into consideration and thus their results are largely inconclusive.
Now that you know the basics of this “miracle” workout, get out and start HIITing. The effects are complicated but do know that you’ll be sweating when you’re done.