The Other 10% Rule

Fast uphill running. Photo: Ian Sharman

Before I start, this isn't a post about how men or women are 'better' than each other. This is just a simple and high level look at stats and comparisons between the sexes. I've met women who are made of granite as well as men whose wills could slice through diamond. Pretty much anyone who undertakes an ultra is unusually strong-willed.

We already have age-grading that allows a degree of comparison between the sexes and ages. But it assumes that the records (especially age-group records) are equally as impressive for men and women, plus that the record is equivalent to the fastest non-masters runner. If either the men's or women's record is relatively more competitive then it skews the results of that sex. More on this in the conclusion.

What is the other 10% rule?

We've all heard about the 10% rule for increasing mileage week-on-week to avoid getting injured, but there's a more precise relationship I've noticed throughout watching the Olympics all my life. The two events that most captured my imagination, the 100m and the marathon, had a relationship between the best men's and best women's record times. Doing simple calcs in my head I could see it was about a 10% gap - women's times were around this much slower than men's times. It seemed to roughly apply across a lot of track and field events, so I thought I'd see how exact that figure is and what it says about ultras.

I've heard people state that at longer distances women have an advantage and I know that scientists predicted the female marathoners would catch the men's times within a short period of time. Unfortunately they based that off simple extrapolation from women's times improving faster than men's in the past when the women's field became more competitive, while the men's already were.

Is there an advantage for women in ultras? Are they more efficient and physically superior for these types of endurance events? Or perhaps they're mentally stronger, able to withstand more pain or are more determined? If so then we'd expect to see that showing through in results at the most competitive ultras and the fastest times by the best athletes.

The stats

Below are the world bests on any surface for various running distances and events for men and women. I've split these into four categories, with the first three being Olympic or at least fully professional and competitive distances - Sprints, Middle Distance and Long Distance. Then I've separated ultra distances below because these don't tend to have the same deep level of full-time pro athletes as the distances up to the marathon. The professional distances are where I'd expect to see enough competition to make the records be a good representation of the best athletes in the world ever at their respective events.

TABLE 1: Olympic/Professional Distances

Distance (All Surfaces)	Men	Women	Percentage Difference	Notes
100m	9.58	10.49	9.50%	Women's record by Florence Griffith Joyner (USA) record has some doping questions, never proved
200m	19.19	21.34	11.20%	Also a Flo Jo record yet relatively less impressive, doping or not
400m	43.18	47.6	10.24%	Women's record by Marita Koch (East Germany) during period of known doping by Eastern Bloc
Avg for sprints			10.31%
800m	01:40.910	01:53.280	9.50%	Women's record by Jarmila Kratochvílová (Czechoslovakia) during period of known doping by Eastern Bloc
1500m	03:26.000	03:50.460	11.87%
1 mile	03:43.130	04:12.560	13.19%
Avg for middle distance			11.52%
5000m	12:37.350	14:11.150	12.39%
10000m	26:17.530	29:31.780	12.31%
Half	0:58:23	1:05:40	12.48%
Marathon	2:03:23	2:15:25	9.75%	No woman other than Paula Radcliffe has broken 2:18, showing just how special her record is
Avg for long distance (pro)			11.73%

Source: IAAF 

What this shows is that it's rare for female world bests to be within 10% of the men's time. In fact, the two distances that made me think about this relationship are two of the toughest and most impressive female records. Both Flo Jo (100m) and Paula Radcliffe (marathon) have run records that have barely been approached - Paula's marathon time is a decade old and is so good it's almost a 3-minute gap to the next best female time, while the men's marathon record has numerous other runners within 1 minute, plus it's only 1 month old at the time of writing. Flo Jo's record is even older.

What seems most notable to me for these Olympic distances is that getting within 10% of the men's performance is the sign of a mind-blowing record. And that's for the most fiercely fought events in world running!

How does the 10% rule relate to ultras?

Already it can be seen that most women's professional distance records are more than 10% slower than men's records. So what about the increasingly competitive world of ultrarunning? I'd argue that the only ultra races that have a long history and truly deep fields on both the men's and women's sides are the South African road ultras - Comrades and Two Oceans.

TABLE 2: Ultra Distances

Distance (All Surfaces)	Men	Women	Percentage Difference	Notes
50k	2:43:38	3:08:39	15.29%
Two Oceans (34.8 miles)	3:03:44	3:30:36	14.62%	The 50k records were the same runs as these records, as a 50k split
Comrades Down Run (55.5 miles)	5:20:49	5:54:43	10.57%	Better representation of 50 mile comparisons as 50 mile distance wasn't raced at the top level by women outside of Comrades
100k (Ann Trason)	6:10:20	7:00:47	13.62%	Second best female 100k time by Ann Trason (USA) - see below for reason
100 miles	11:28:03	13:47:41	20.29%	Not raced by women at the same deeper competitive level as by men in 1980s-2000 when male record set
24 hrs (m)	303,506	254,425	19.29%
UTMB (trail)	20:34:57	22:37:56	9.96%	Records set same year so weather not a differential
WS100 (trail)	14:46:44	16:47:19	13.60%	Records set same year so weather not a differential
Avg for long distance (ultra/semi-pro) without Tomoe Abe			14.66%
Avg for long distance (ultra/semi-pro) with Tomoe Abe			13.72%	More info about the Tomoe Abe record here
Other Results of Note:
50 miles	4:50:51	5:40:18	17.00%	Top women ran much faster for 50 miles at Comrades, so that's a better comparison
100k	6:10:20	6:33:11	6.17%	Record by Tomoe Abe (JPN) who was a professional marathoner

Sources: IAU, race websites

The 10% rule almost applies to Comrades, the larger, older and more competitive of these two races with a longer history - a 10.57% difference. But not so much for Two Oceans, despite the record holder for women being the same person as at Comrades, Frith van der Merwe.

It certainly doesn't hold up for most of the events in the table, possibly due to lower female participation but also because Yiannis Kouros spear-headed huge improvements in men's ultra road and track running. In fact, his dominance is so great that his 24-hour record is a half marathon ahead of his next closest challenger!

Most trail ultras are either too new or have fields that are only a few elite runners deep. So I included the two that have the longest and deepest history of competitiveness, especially since their records for men and women were set in the same editions (2012 for Western States 100 and 2013 for UTMB), removing differences in trail conditions, distances or weather. What stands out is that Rory Bosio's record at UTMB is a truly competitive record relative to a very impressive men's record.

The 10% rule doesn't seem to apply to ultras as much, probably due to it being a male-dominated sport with deeper men's fields to push the men's limits closer to a theoretical maximum than for the women. But women like Frith and Rory show that women's records at the top level can hit around 10% off the men's bests.

Women's records at some ultra races are indeed within 10% and sometimes women win outright, but I'd argue that those results reflect more on the lead women being closer to the best of the best than the lead men in those cases. That's why I've only included the most competitive races that are directly comparable. A separate question is whether women below the very top level race better than equivalent men, since women's finish rates are often higher than those of the their male counterparts. However, that's a different angle and is where I'd expect to see sensible tactics and a lack of testosterone-fueled over-exuberance giving women a relative edge on average...but not enough to overcome the physical attributes that lead to the 10% advantage at the upper limit of what's possible.

The one clear outlier is Tomoe Abe's 100k world best for women, which is so fast it's 27 minutes better than the next result and this is the only ultra result I can find from her. She was a professional road marathoner with a 2:26 PR, roughly equivalent to many of the fastest male 100k runners. So I've excluded her because she was a pro marathon runner while the top men weren't (making her closer to the female 'potential' than the men may have been to the male 'potential'). Her 100k time is around what would be expected from a male runner with an equivalent marathon time and very good aptitude for road ultras.

Predictions

Although the 10% rule doesn't hold up perfectly throughout, it looks like it roughly applies when both the men's and women's records are equally close to the best possible results a human can achieve. This doesn't seem to be the case in most truly top level ultra events yet, but if we use it as a benchmark, what kind of times might we see at ultra events by women as the fields get deeper and more astounding women push each other to their limits?

Note that the predictions below have an obvious caveat - the weather and conditions need to be equivalent to compare results year-on-year. So Timmy Olson's Western States 100 record was run in near perfect conditions for the course and no man or woman is likely to get an equivalent performance without equally good weather. If they manage it it tougher conditions, it's not equivalent - it's better.

TABLE 3: Predictions For Women's Times For Selected Fast Men's Global Records

Distance (All Surfaces)	Men's Actual Record	Women's Predicted Record	Women's Actual Record	Notes
Two Oceans (34.8 miles)	3:03:44	3:22:06	3:30:36
Comrades Down Run (55.5 miles)	5:20:49	5:52:54	5:54:43
100 Miles	11:28:03	12:36:51	13:47:41
24 hrs (m)	303,506	275,915	254,425	That's 171.5 miles - 1 mile short of the US men's 24 hr record!
UTMB (trail)	20:34:57	22:38:27	22:37:56
WS100 (trail)	14:46:44	16:15:24	16:47:19
Rocky Raccoon 100 (trail)	12:44:33	14:01:00	14:57:18
Leadville 100 (trail)	15:42:59	17:17:17	18:06:24
Grand Slam (trail)	69:49:38	76:48:36	79:23:21
Hardrock 100 (trail)	23:23:30	25:43:51	27:18:24
Spartathlon 153 (road/trail)	20:25:00	22:27:30	27:02:17
Rim2Rim2Rim (Grand Canyon)	6:21:47	6:59:58	8:15:51
JFK50 (trail)	5:34:58	6:08:28	6:11:59
TNF100 Australia (trail)	9:16:12	10:11:49	11:01:08
Speedgoat 50k (trail)	5:08:07	5:38:56	6:17:02
Vertical K (trail)	0:30:26	0:33:29	0:36:48	Included this one for fun, despite not being an ultra as it's very competitive

Sources: IAU, race websites

Conclusion

I think the 10% rule stands up as a way of measuring potential. It only applies when the men's best times are truly at the top end of what's physically possible, but even allowing for that it can compare when women have out-done the men on a given course, allowing for differences in weather etc. Distance running women in that list include Paula Radcliffe, Frith van der Merwe, Tomoe Abe and Rory Bosio with several other women around that level.

So I'd argue that men have been 'virtually chicked' ('chicking' refers to a woman passing a man in a race) if a woman runs 10% slower than them...look out all those guys that thought they could beat Rory or Ellie Greenwood currently! This would also allow for a ranking at a race based on times adjusted for the sex of the runner.

Age gradings could also be altered to allow for when the record for one sex is relatively less impressive than that of the other sex by making the gap in theoretical fastest times be 10% (ie whichever record is relatively slower gets improved to retain the 10% gap). That is likely to apply when the female field is a lot smaller than the male field, but makes the amazing masters' records of people like Meghan Arbogast even more impressive.

Apologies if I offended anyone with this article, but I found it fascinating to look at the results and comparisons for all types of running. The data is as objective as I could make it, but I'm sure many would disagree with even the sentiment of what I was comparing.

Exploring The Limits Of The Body

I started the Javelina Jundred 100-miler yesterday, but didn't finish. Normally that would feel like abject failure but this year I feel I've been getting a better idea of when I can push and when to cut my losses.

After the Grand Slam through the summer, I was able to push myself harder than I'd previously thought possible, largely thanks to having Nick Clark to race against. To me ultrarunning is about finding out more about myself and not getting constrained by what I think should be possible. My instinct told me that four 100-milers in a 10-week period would lead to gradual deterioration of my body (and mind), yet some aspects of my fitness actually improved. At the end of each race I was completely spent, but more so after the final 100, the hardest and slowest course at Wasatch.

Since I seemed to still be in one piece after the summer I made a late season decision to run Javelina since it's a faster course and the organizers, the Coury brothers, put on such excellent events. Each of the Slam races was either three or four weeks apart so I thought a seven week gap might be ok. If I didn't try I know I'd wonder for the future whether the summer had made me reach a new level of fitness or worn me out.

So I started at Javelina and felt surprisingly good on lap one of 6.5. It was so much fun running and chatting around sunrise to Hal Koerner, Joe Grant and my Scott team-mate, Jeremy Humphries. Even better when we went through the first loop in course record pace, all feeling good. Things stayed together for most of the second loop too and we all hit the end of loop two within a minute of each other, in 3:54 for 30.6 miles.

By that point I was starting to feel a little tired, but wasn't worried as 30 miles is a long way and the pace was good. However, in the next few miles my legs felt dead with nothing left in the tank. I tried hiking to kick-start things but after a couple of miles of switching between walking and running I found I could barely run. I kept walking for the rest of that loop but even 50ft of running felt like too much, so I opted to just walk in to the end of the loop, worried that pushing more might dig me into a deep hole for the next few months.

Although it was hot, there was a light breeze that meant it felt fine as long as I kept dousing myself in water. The walk back was genuinely pleasant as the desert looked beautiful plus the number of runners in Halloween costumes certainly adds to the experience - it's amazing they do that in the desert heat.

I wasn't feeling down about things not working out since 2013 has been a great year for me. Instead I was glad I took a chance to try one more ultra this year and that I picked an event as fun as Javelina. If I never fail, success seems hollow as it means I'm staying within my comfort zone.

The initial lead back broke up over laps three and four, leaving Hal in front and he won in 14:56 with Catlow Shipcek second and Joe in third. Jeremy got progressively more injured throughout and had to drop at mile 70 with a suspected broken foot, so hopefully it won't turn out to be that bad. Nice work by all the runners and this is a race I'd highly recommend and will return to.

Full results here when available.

Back To Running

I felt a little uneasy not running for two weeks after Wasatch 100 since I already had so much time off running in-between each 100 miler this summer. It may sound weird, but I felt like I really took things easy for most of the past few months - I just had four major days of running dawn 'til dusk.

So it's been surprisingly liberating to try to run fast again in the past week after a lot of plodding and hiking. To kick things off I entered the Coastal Trails Diablo half marathon as it's just down the road and I wanted an excuse to push hard on Mt Diablo as it's my favorite place to run in the Bay Area. A few weeks ago the mountain was on fire (apt, given the name) but luckily the majority of trails were basically ok. It uses the most direct route to the summit from Mitchell Canyon Trailhead, a 6.7-mile, 3,400ft climb up fire-roads and single-track then back again at full speed.

One thing that appeals is that I want to chase the Fastest Known Time (FKT) for the climb and descent and the quickest that I can find evidence for is the 1:49:20 CR from this race in 2012. I think a Sage or Max King could run low 1:30s, so as long as they stay away I think I've got a shot and will give it a few attempts through the winter.

In this race I got to chase Jonas Oppedal but was five to six mins back by the summit (1:12 was my split), before hammering after him in a fun chase that even didn't get me within sight. He ran a tantalizing 13 seconds over the course record and I was 81 seconds behind him in 1:50:54. Strava info here.

Another great event from Coastal Trail Runs, one of the best reasons to live in the Bay Area.

Also, UltraSportsLive.tv made a video of the race showing some of the great trails and views on Diablo:

Are We In A Trail Ultrarunning Golden Age?

Timmy Olson's 2012 Western States Record. Photo: irunfar

Selected World Records/Bests (All Surfaces)

50k:
Men - Thomson Magawana (RSA) 2h43m38s (1988)
Women - Frith Van Der Merwe (RSA) 3h08m39s (1989)

100k:
Men - Don Ritchie (GBR) 6h10m20s (1978)
Women - Tomoe Abe (JPN) 6h33m11s (2000) [I believe there were issues with a lack of drug testing making this potentially unofficial]

100 miles:
Men - Oleg Kharitonov (RUS) 11h28m03s (2002)
Women - Ann Trason (USA) 13h47m41s (1991)

24 Hours:
Men - Yiannis Kouros (GRE) 188.63 miles (1997)
Women - Mami Kudo (JPN) 158.11 miles (2009)

Arguably the end of the last century was the golden age for road ultras since most of the current road and track world records were set then (see above for a selection, sourced from the IAU here) but in recent years the focus has switched to trails.

As trail and mountain running has increased in popularity thanks to stars like Kilian Jornet, deeper fields of faster runners have been taking down records on a weekly basis. Some of these are mind-blowing and the old records were described by some as untouchable, like Ann Trason's Western States 100 record that Ellie Greenwood destroyed in 2012 by 50 minutes.

However, I'm not sure why the quality of runners in the flatter ultras plateaued in general, especially in the US and UK. Yes, road races at marathon distances have got bigger prize money now but it's not generally Americans (and certainly not Brits) that are at the front of these African-dominated races. There are less road runners around the top level (like sub 2:20 male marathoners) than there used to be in western countries, something I'd ascribe partly to increased wages with longer work hours making a tough life of training more difficult and less appealing, relatively.

Anyway, back to my original point that trail running talent is on the rise. Course records and Fastest Known Times ("FKTs") keep falling to give a good indication of what some runners are capable of, but the more impressive thing is how deep fields are becoming, especially on the men's side. Several times a year a race gets described as 'the most competitive ultra of the year' and I personally love the fact there are so many events where runners can race against a good selection of the best runners around. Times that would have been guaranteed to win races in the past now end up off the podium so everyone has to raise their game and it makes us all better runners. Ann Trason dominated women's fields for years and basically raced the men rather than other women, but who wouldn't have wanted to see her in her prime against the likes of Ellie Greenwood and others?

I wonder how much better runners can get. Cam Clayton suggested he could run a 14hr Western States and it'll be fantastic to see continuing mind-blowing performances. The addition of fast road runners who also specialize in mountains has made a difference. However, many of the top runners have never and will never race on roads - think of Kilian's disdain for the 12 miles of roads at UROC100k!

Some marks I hope can be reached over the next few years in a few of the classic trail ultras are below. I think they're possible with the help of perfect running weather and several fast runners pushing each other.

UTMB: sub 20hrs for men, sub 22hrs for women
Western States 100: sub 14h30m for men, sub 16h15m for women
Leadville 100: sub 15h40m for men, sub 17h30m for women
Any trail 100: sub 12h30m for men, sub 14hrs for women
Grand Slam: sub 68hrs for men, sub 75hrs for women
JFK 50: sub 5h20m for men, sub 6hrs for women

Some of these are likely to be more feasible than others and I think the UTMB and WS records are most likely to fall due to the higher level of competition at those races year in, year out.