Six minutes of high-intensity exercise may help maintain a healthy brain and delay neurodegenerative disorders - study

We all know exercise is good for us but it turns out just six minutes of intense exercise can boost your brain's health.

That's according to the latest research from the University of Otago.

Working up a sweat comes in many forms especially when it comes to high-intensity training.

"There's normally some weights involved in it, there might be some speed training involved in it, but it's something that's going to get the heart rate up really, really quick - quick recovery - and then repeat," said True Woman's Fitness & Well-being personal trainer Sheree Stoneham.

But working up the motivation to work out isn't always easy. The good news is, shorter bursts of intense exercise - even just six minutes of it - can help make a difference.

The study compared 90 minutes of low-intensity cycling, six minutes of vigorous cycling, fasting for 20 hours and a combination of exercise and fasting.

It found the shorter, more intense workout was four to five times more effective. That's because it increases what's called 'BDNF' levels in the blood. It helps boost your brain's health or delay the onset of certain disorders.

"BDNF promotes brain neuron survival, maturation development, memory formation and all the rest of it. Basically giving you a longer life when you still know who you are," said Auckland University Centre for Brain Research director Sir Richard Faull.

Why this happens is not yet clear, but researchers suspect it is related to the brain switching from using glucose as its primary fuel to using lactate produced during high-intensity exercise.

"This 'substrate switch' allows the brain to utilise alternative fuels and initiates the production of key neurotrophic factors such as BDNF," said study leader and former Otago researcher Dr Travis Gibbons, of the School of Physical Education, Sport and Exercise Sciences.

"Another possibility is related to the 20 percent increase in the concentration of circulating platelets that occurs with exercise, as platelets store a large amount of BDNF."

And while there have been many studies on BDNF using animals there's limited research exploring how to naturally increase the protein in humans.

"We're joining the dots from animal studies, as well as evidence that life-long exercise maintains brain function as we age," said Dr Kate Thomas, from the University of Otago Department of Surgical Sciences.

Sir Richard said aiming to improve that function is a no-brainer.

"Having a good healthy brain has got to be the best thing in the world - because your brain is who you are and what you are."

And if that's not worth six minutes of your time, what is.