What’s the shortest amount of time you can move your body and still reap health benefits?

That’s the question researchers with McMaster University investigated in a recent study published online in the journal PLOS One (Plahs One).

Their answer? Fewer than three minutes of intense, intermittent exercise cushioned by 27 minutes of warm-up, recovery and cool-down exercise per week is what’s needed for good health.

In 18 sessions over six weeks, study participants exercised with a two-minute warm-up, cycled at their top capacity for 20 seconds and recovered for two minutes. They repeated this twice more, then cooled down for three minutes.

By the six weeks’ end, researchers found exercise spurred participants’ skeletal muscle oxidative capacity, or their muscles’ ability to produce and sustain power. Their peak fitness levels and blood pressure also improved.

Researchers from the Florida campus of The Scripps Research Institute say intense exercise’s benefit may come from the activation of your body’s fight-or-flight response, which triggers a protein called CRTC2.

The protein causes growth in the contracting muscle. When the researchers altered mice to express the protein without exercising, their muscles showed the same molecular changes that would have happened during a workout. When the genetically altered mice did an exercise stress test, muscle size increased by 15 percent.

The Scripps researchers say that when your adrenaline system is turned on during intense exercise, it targets and improves specific muscles. They think it’s to prepare you for the next time you may have a fight-or-flight response. Exercisers reap these benefits in the form of high-intensity workouts.

But if you haven’t been active in a long while, don’t be worried: The McMaster researchers say the workouts can be scaled to everybody’s level, regardless of your abilities.