Is 4 Seconds of HIIT Enough to Make You Healthy?

Exploring Intensity

Is 4 Seconds of HIIT Enough to Make You Healthy?

At Cardio High we are amused by studies to find the absolute smallest amount someone can exercise and find benefit. The New York Times made the 7-minute workout a popular routine a few years ago, with claims that 7 minutes of exercise a few times each week would make an incredible difference in one’s health and energy. Gretchen Reynolds, the paper’s primary health writer, wrote a book called The First Twenty Minutes, which makes the case that if you can go from zero minutes to just 20 minutes each week, you will experience amazing health benefits. 

Researchers led by Martin Gibala at McMaster University in Canada started studying the benefit of short bursts of exercise in people. They did detailed studies on the changes in human biology with just ONE minute of exercise. Dr. Gibala documents these studies in his book The One Minute Workout

For some people exercising at a high intensity level for one minute is too hard. They need to break it down into 20-second bursts repeated 3 times. But is there an even shorter burst that might feel easier?

Well, researchers at the University of Texas aimed to use 4-second bursts to see if those brief sprints would have health benefits. They recruited 39 people who were over 50 years and lived a sedentary lifestyle. They were asked to repeat the 4-second bursts followed by a 56 second rest. As the study went on the researchers decreased rest to 26 seconds and increased the number of sprints to 30, which was 2 minutes of intense exertion in a 15-minute workout. The people in the study improved fitness 10%, increased muscle mass especially in the legs and most importantly decreased stiffness in their arteries. 

You might ask why are they so focused on brief bursts? There are two major factors. The researchers have learned that if a workout feels too hard, people will not stick with it. People in the study enjoyed the workouts and felt they could go hard for 4 seconds. So, if your coach or trainer is asking you to go all-out for 60 seconds, just remember that you don’t have to listen. You can go all out for maybe 20 seconds or 10 seconds and you will still be getting benefit.

If that makes it more enjoyable, perhaps modify what the coach is asking of you. And, it’s difficult to exercise all alone without the motivation of a trainer or without special gear. But if you have a staircase, you can bound up the stairs quickly and then walk up and down and repeat. It’s better than doing nothing. 

– Mark G.