Aussie have never been slower – Basic Stats Analysis

Article by Ivanka Nikolova Ph.D.

Participation in marathons has increased x 8 over the last 20-years – however data shows that Aussie marathon runners are slowing down. Why is this?

*Note from editor: This is a generalised stats analysis that has not taken into account all sub 3 hour data and other factors but is an interesting read non the less.

Researchers from crunched all the Aussie marathon results from 2000 to 2016 and concluded that Aussies have never been slower.

The Usual Suspects

What are often cited as possible reasons for this trend are:

  • The increased participation;
  • The increased numbers of female participants;
  • The increase of the average age of the participants.

What they have found is that these reasons can not explain the trend entirely. Let’s see why.

Increased Participation

Numbers of marathoners have increased in the last 17 years.

The logic is that the more popular marathon running becomes, more and more unprepared participants join and they drag the average down.

But from the data we can see that everyone is slowing down – fast and slow.

Also, if we look at the finishers by time brackets we can see that the percentage of people, who just walk the race has been and still is minuscule.

Also, the biggest increase is in participants with average finish times. So, this means that the participation increase is not the main culprit here.

What about women?

As we know women are on average slower than men and with more women, the average time goes down.

But, though women are slower in general, men and women are slowing down equally. Also, female numbers are rising less than male numbers.

However, the proportion of women has slightly increased and being slower makes them about 70% responsible for the general trend.

But, it’s important to know that even men are equally slowing down, so even if just men were entering the race, there still would be an increase in the average.


For Aussies this argument is mute, because the average age of participants is actually going down.

What about health?

What Andersen and Nikolova have found is that obesity and hypertension correlate strongly with the slow-down trend.

And since obesity and hypertension are chronic conditions it’s worth examining their long-term effects. The obesity and hypertension rates correlate strongly also with the finish times after 3 years.

Correlation is not causation and we can’t be sure that these results are the complete and only explanation for the slowdown of Australian marathoners. But it is worth noting that the deteriorating health has an impact even on active and health-conscious marathon runners.

By Ivanka Nikolova Ph.D. – RunRepeat