If you're not familiar with the concepts behind high-intensity interval training (HIIT), it can be difficult to decide whether or not you want to try it out. Check out this beginner's guide to the workout trend and make an informed decision.

What is HIIT?

Simply put, HIIT is a type of exercise training where the participant alternates between short bursts of intense activity and periods of less strenuous activity. Intense is defined as an activity achieving a heart rate between 80% and 100% of its maximum output (220 minus age). For example, a 30-year-old person would have a maximum heart rate of 190 beats per minute.

There are no agreed-upon standards for what an optimal HIIT workout would be. As long as there are intervals of intense activity and rest, it's HIIT. This can include:

  • 20 seconds of intense activity, followed by 40 seconds of rest for 10 minutes.
  • A one-minute bout of extreme exercise, followed by a one-minute period of rest, for a total of 20 minutes.
  • Four minutes of action, with three minutes of rest in between, four times.

These are only a few examples. A quick internet search will bring up many different routines. The common link between them is the intervals of intense activity followed by periods of rest.

Proven benefits of HIIT

  • HIIT produces greater benefits to your cardiovascular health, compared to traditional endurance training. There are greater improvements to VO2 max (the maximum amount of oxygen your body can use and, generally, a great indicator of overall cardiovascular health). It also takes less overall time to see these benefits.
  • HIIT combats insulin resistance, decreasing the chances of type II diabetes.
  • HIIT yields fast results. Muscular endurance is quickly enhanced with HIIT. You could start seeing results in a matter of weeks rather than months.

HIIT versus continuous exercise

While HIIT uses varying degrees of intensity at different time intervals, traditional continuous exercise uses a consistent level of intensity throughout the workout. This is the normal way to exercise and has been used forever to achieve results. The main benefit of HIIT, in comparison, is that the workouts themselves take shorter amounts of time to produce similar results (for those who are not already physically fit). Unfortunately, those who are already fit don't see the same level of progression.

Cons of HIIT

While the benefits of this method are numerous, there are definitely things to consider before starting a regimen. Some of the cons are:

  • High barrier to entry. While the workouts are significantly shorter than standard continuous exercises, it's also much more difficult to complete. Getting up to 80% to 100% of your maximum heart rate takes a lot of effort. If you equate that 20-minute HIIT workout with torture, you are less likely to do it next time.
  • No proven weight loss benefits. Although the key to weight loss is always an improved diet, continuous workouts help burn calories and allow you to shed pounds faster than diet alone. While, as we've seen, HIIT is extremely helpful to overall cardiovascular health, it's actually less effective than you might expect at promoting weight loss. This is because HIIT takes less time. So, while it's really nice that you don't have to work out as long to get improved heart health, it also means that you're not expending as much total energy. That means you burn fewer calories and lose less fat.

Hopefully, you now have a deeper understanding of what HIIT is and whether or not it's something you'd like to try. Before starting any new exercise routine, you should consult your physician to assess in greater detail whether it's a safe option for you.

No matter what training philosophy you subscribe to, what really matters is that you're out there being active on a regular basis. Both HIIT and continuous exercise will make you a healthier person, so give them both a shot and figure out what you enjoy the most.