Quirks and Quarks

One minute of exercise a day can keep you healthy

New science suggests high-intensity interval training keeps cells young.
Science is showing that the most efficient and effective way to reap the benefits of exercise is through high intensity interval training, otherwise known as HIIT. (Getty Images)

You've probably seen people in the gym do this, or done it yourself. You hit the treadmill, run fast, back off, run fast again... you get the picture.

A new study published this week in Cell Metabolism breaks down why high-intensity interval training (HIIT) can also help fight the effects of getting older.

Interval training is this notion of peaks and valleys. So literally going hard and backing off, and repeat.- Dr. Martin Gibala

Dr. Matt Robinson is an assistant professor of kinesiology at Oregon State University, but he conducted the study during a postdoc at the Mayo Clinic.

One of the theories of aging is that as a person gets older their muscle proteins start to accumulate little pieces of damage much like a car would accumulate rust over time.- Dr. Matt Robinson

The proteins he's talking about are the ones used inside muscle cells to make and maintain the mitochondria. Mitochondria is where our cells get their energy. As we age, the mitochondria start generating free radicals. 

So if you don't buff out that rust, it'll spread.

To study effects of HIIT on these processes, Dr. Robinson devised a study with four groups of older and younger people.

One group did the high intensity interval training on an exercise bike, three times a week. That included a warm-up, then four, four minute intervals separated by three minutes of rest. Another did resistance training, so that's using free weights or machines to lift weights. And yet another combined both moderate cardio exercises — like riding an exercise bike — and resistance training. The final group was a sedentary control group.

The HIIT training appeared to protect against the accumulation of damaged proteins.- Dr.  Matt Robinson

That study was looking at cellular effects of four, four minute exercise intervals. So, 16 minutes of intense exercise a day.

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Dr. Martin Gibala is a professor and chair of the Kinesiology department at McMaster University in Hamilton, Ont. He's also the co-author of a new book called The One-Minute Workout. He says that time we spend exercising really intensely can go down even more… to one minute per day. 

Sounds like click-bait, but it's not.  

The following interview has been condensed and edited for clarity.

Bob McDonald: What got you into looking at the effectiveness of very short workouts?

Martin Gibala: Part of the reason is we know the number one cited reason why people are not physically active is lack of time. Now that's clearly an excuse for some folks but many of us lead very busy, time-pressed lives.

The one-minute workout really involves three 20 second hard bursts of exercise. (Brandon Wiggins)

OK, walk me through the one minute workout.

The one-minute workout really involves three 20-second hard bursts of exercise. Now that's typically set within a 10-minute time commitment. So start to finish, 10 minutes. You have a short warm-up, then you do those three 20-second very hard sprints with a little bit of recovery in between. And then a short cooldown, so start to finish 10 minutes. But within that one-minute, a very vigorous exercise.

And that's it for the day? 

That's it. And we've tested it on a bike, we've recently tested it using stair climbing. So many of us live in office or apartment complexes work in office towers and so stairs are a very readily form available exercise. So I don't think the mode is particularly critical.

A competitor in the UK Ironman 2015. (Francis Franklin)

Let's go through the science here. How does the one-minute method stack up to "pounding the pavement" type of exercise?

In the lab we had one group do the three 10-minute sessions per week, so that's a 30-minute time commitment, and within that that would be three minutes of very vigorous exercise. And we had another group do 50 minutes of the more traditional, continuous moderate exercise three times a week. So typical public health guidelines.

What we found after several months of training was that the two groups improved by the same extent.- Dr. Martin Gibala

So the improvement in their cardio-respiratory fitness was the same on average. The improvement in their insulin sensitivity, which is a measure of how well the body uses blood sugar, was the same. Even changes inside their muscle—we took biopsies and measured changes in mitochondrial content and some cellular compounds. And they increased to the same extent, even though the interval group was involved in five-fold less total exercise and a five-fold lower time commitment.

Were you surprised by that?

It was consistent with what we hypothesized, but I was surprised at the equal improvement between the groups. Now obviously there's individual differences there some people responded more than others but the fact that, on average, especially that improvement in their cardiovascular fitness was the same on average identical on average. That was quite a stunning result to me.

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