Are women runners catching up?

Are women better long-distance runners than men? Health24’s Fitness expert, Dr Ross Tucker, looked into this particular battle of the sexes.

Analysing the entire distance range
To test the theory that women are better long-distance runners than men, we looked at the performance differences between men and women across the entire range of distances, from 100m to ultra-marathon. There are flaws in this method: far fewer women run the long-distance events in particular (which reduces the depth of ability available), and also women have only been running competitively for perhaps 40 years, compared to almost 100 for men.

The analysis showed that, rather than catching up to men as the distance increases, women (at the world’s best times, anyway) are in fact always about 10% slower than men. The reason for this at the shorter distances is the testosterone advantage enjoyed by men (called the "hormone gap" by one scientist).

(One interesting observation regarding this is that in the last 10 years, as drug testing has become tighter, women are in fact falling even further behind the men than they were in the 1980s, when women were arguably pumped full of steroids.)

We concluded that it is highly unlikely that women will ever catch up to and pass men, at least when we look at the very best athletes.

Another way to approach the question
The above-mentioned study probably isn’t the only or best way to go about answering the question, "Are women better distance runners than men?" Does it answer the question to know that Haile Gebrselassie’s world marathon record is 8% faster than Paula Radcliffe’s? Or that Kenenisa Bekele’s 5000m world record is 10% faster than Meseret Defar’s?

Only partially.

A better way to pose the question may be to ask whether a woman is better than a man as the event gets longer. This is different from asking whether WOMEN are better than MEN as the distance increases, because now we are only interested in comparing one man to one woman.

The research – a simple study
About ten years ago, in an attempt to answer this question, University of Cape Town scientists looked at a large group of runners from the Two Oceans and Comrades marathons. They found out what the runners’ best performances were at distances ranging from 5 km all the way up to Comrades. See the Figure below:

This graph shows that when you look at the SAME person across a range of distances, you find that the running speed is higher in men from 5 km to 56 km, but that the gap between men and women decreases progressively, until eventually, we hit the Two Oceans at 56 km, and then men and women run at the same speed. Go one step further, to Comrades, and the women are faster than the men.

Remember though: the difference between this method and the world records we looked at earlier is that here we are looking at the same person across a range of distances, not the fastest single person in each event. In other words, we’re asking whether a woman who runs as fast as a man at shorter distances is more or less likely to catch up over longer runs. And the answer is a resounding yes!

The implications? Choose your distance
You may be thinking this pattern is obvious, because the physiological advantages – testosterone, more muscle, lower body fat, larger hearts, more oxygen-carrying red blood cells etc. – are likely to have a greater effect in the shorter events which require ‘explosive’ power and speed. But as the distance increases, those advantages are eroded, so a woman who is comparable with a man over a shorter distance will come into her own over the longer distances.

Let’s take the example of Bob and Alice, who both regularly do club time-trials. If they run a 5 km time-trial in the same time, then whenever they run a 21 km race, the safe bet is Alice will win, because she gets relatively stronger as distance increases. And if they both ran the Comrades, then it’s a pretty safe bet, most times, that Alice will finish ahead of Bob. This is assuming the run goes according to plan – a lot can go wrong over 56 or 90 km – so this might not always work out perfectly. But, on the whole, women who are reasonably close to men in shorter races will find they get to lead the way in the ultras.

The reasons
The first reason women are relatively better at the longer runs than men is metabolism- or energy- related. During the ultras, the body’s main energy source is fat, because the carbohydrate stores are limited in volume. Therefore, women have greater energy reserves to call upon and may even be better at making use of the available energy. At shorter distances, this is not a concern, since carbohydrates like glycogen are the main energy source. Besides, the strength advantage men have as a result of larger muscle mass makes them the short-distance kings.

The second reason is differences in pacing strategy. Some fascinating research has shown that women tend to pace themselves more evenly than men, and seem to be less affected by external factors (like crowds, rivals etc.) than men.

In one study, researchers tried to confuse runners by manipulating a clock to run either faster or slower. The women weren’t fooled: they went about their business as usual. The men, however, ran either five minutes longer or shorter over about 30 minutes of exercise.

Could women have a more finely tuned internal clock that allows them to judge distance and pace? More research needs to be done on this, but next time you watch a race, consider that the hordes of men who surround the lead women (often to get on TV, true) benefit enormously from the steady pace they set.

It’s unlikely that women will ever catch up to and beat men at the very top level, where the elite and world record-holders play. But for more ordinary exercisers, women do seem to have a "relative" advantage over the longer-distance events, getting progressively better than men as the distance increases for each person. The bottom line is that we all have strengths as runners – for women, it’s likely to be longer-distance events.

More women are running
Setting aside the gender rivalries for a second: one important statistic is that most of the growth in running in the last few years has been among women. Inspired by running’s health benefits and social aspects, more women are hitting roads and treadmills than ever.

Though this trend hasn’t quite made it to the Comrades yet, where only 18% of this year’s finishers were women, the running community is the stronger for it.

So here’s to continued growth in women’s running. At the very least, as a women runner, you’ll give a few men good reason to try to run faster!

- (Ross Tucker, Health24, November 2007)