The longer the race, the stronger they get

The longer the race, the stronger they get

The longer the race, the stronger they get

Some ultramarathons are run on very strange courses: through blazing hot deserts, frozen land at the North Pole, on muddy horse trails and over steep mountains.  My three ultras were relatively civilized in comparison:  50 miles on a half mile trail, 100 miles on a one-mile paved loop and 24 hours on an indoor track.  Recently I read about an ultra, which is in a class of its own in weirdness, that revealed something amazing about women ultra-runners.

Called Big’s Backyard Ultra, the fiendish design is quite simple.  The goal: each person must run a four-mile loop within an hour.  It might take 30 minutes or 59 minutes.  The runner rests until the bell rings, and the next lap starts.  It is ridiculously easy at first, but as the hours go by, it becomes harder.  After 24 hours, it gets really tough, and after 48 hours, it becomes really, really tough.  They just keep going, as more and more drop out from exhaustion.  The last one still moving is declared the winner.

The winner of this Tennessee race, and the winner of many other ultras, was a woman.  Maggie Guterl traveled 250 miles in 60 hours to outlast all other competitors, most of them being men.  The unusual design of this race takes speed and strength out of the equation, leaving pure endurance as the only important factor. This makes it possible for men and women to compete on an equal basis.  Because men have larger amounts of testosterone than women, they have bigger and stronger muscles.  This means they will always be faster and stronger than women.  However, in the world of ultra-running, the male advantage is muted.

Men still win more ultras than women, but this is mainly because there are more males competing.   Women account for only 20% of participants in 100-mile races.  To understand why women do better than men in some ultras, we need to get into some physiology.  Because men have stronger muscles and larger lung capacity, they have a higher maximum vital capacity, VO2 max.  This means that in a race where competitors are going all out, the men will have a distinct advantage. This is even true in the marathon.  Here the race is run at close to maximum capacity and, therefore, women’s times are consistently slower than men.

Once the race is beyond marathon distance, it is not run at maximum effort.  Endurance and efficiency become more important than raw speed.  Women tend to have a high percentage of slow twitch fibers and these are resistant to fatigue.  These fibers are not good for maximum strength contractions, but they can keep going like the energizer bunny.  In addition, women tend to have more fat stores which they can access and metabolize.  Fat releases energy more slowly than carbohydrates.  It won’t give rocket speed, but it is slow burning and lasts a long time.

There are also psychological factors that favor women.  A study of runners in the 2013 Houston Marathon asked each participant to predict finish time.  The men tended to overestimate their ability while women tended to closely predict finish time.  In addition, it was noted that men went out faster than they should and then had to slow down near the end.  Women went out at a more reasonable pace they were able to maintain throughout.  Although women are referred to as the weaker sex, in some respects they may have more mental toughness than men.  This has not been validated by any research, but many women point to the long hours of pain during labor and delivery, as training to endure hardship.

An analysis was designed to get some hard numbers about the limit of human endurance.  When runners in a 3,000-mile race, Tour-de-France bikers, and other elite endurance athletes were studied, researchers came up with a special number: 2.5.  If you take the resting metabolic rate of an individual and multiply it by this magic number, you find the number of calories that an individual can safely burn in a day.  For the average person, this is about 4,000 calories.  Rates higher than this are, of course, possible, but not sustainable for very long periods.  To test this finding, a group of runners completed six marathons per week and were able to keep going for months, as long as they stayed under their 2.5 limit.  The researchers speculate that the ultimate endurance limit may have more to do with the digestive system’s ability to keep supplying energy than anything else.

It is clear now that women have special abilities in the area of ultra-long endurance events.  As the distances become longer and longer, the differences in performance become smaller and smaller, and women frequently outperform men and emerge as the overall winners.  Weaker sex?  Not anymore.