EXCLUSIVE: ULTRA Marathon running appears to have the extraordinary effect of extending life by up to 16 years.

New Victorian research reveals that running long-distance runs can slow the ageing process by protecting the part of the body that stops the genes from fraying.

Runners in The Federation University Australia study had an average age of 43, but their biological age was just 27.

But for those not partial to pounding 40km worth of pavement, the researchers believe similar life-extending benefits could be achieved by high-intensity interval training.

The findings from the state's new university, which combines both University of Ballarat and Monash University Gippsland, challenges old assumptions that extreme exercise had a detrimental impact on the body.

School of Health Sciences Professor Fadi Charchar and PhD student Joshua Denham analysed the DNA of 67 ultra marathon runners to see what the impact of running long distances had on the length of their telomeres.

These structures are made up of DNA and protein and act as protective caps on the ends of chromosomes.

Prof Charchar said telomeres influence how quickly cells age.

The shorter the telomeres become over time; the faster the cells deteriorate.

The findings, to be presented at the Australian Society for Medical Research National Conference, found ultra-marathon runners clocking up 40-100 km a week had 11 per cent longer telomeres.

"This 11 per cent difference adds 16 years to your life expectancy," Prof Charchar said.

State representative of the Australian Ultra Runners Association Sharon Scholz said she enjoys feeling fit and having energy and the sense of accomplishment of pushing her body.

Her husband, Justin, who is also an ultra-marathon runner, said it was great to know that the exercise was extending his life in addition to boosting his fitness.

Prof Charchar said it was still unclear how exercise stops telomeres shortening and what amount of exercise was required to achieve it.

The study is being extended to look at whether high-intensity interval training could have the same effect.

"Not everyone has to run 40km every week, we think that it may be better to do a little bit of high intensity benefit rather than one hour walking," he said.

He said they are also investigating whether the benefits could make positive genetic changes that could be passed on to children.

Lucie.vandenberg@news.com.au