Predisposition & Marathon Potential

Pezz exploring her range

 

Given equal preparation, how much an athlete slows down as the race distance gets longer depends on many individual variables ranging from muscle fiber make-up, to bone structure, to mental wiring and personality.   Some people’s minds and bodies are better suited for longer races and some for shorter races.  I call this aptitude towards different distances their natural predisposition.

It only makes sense then that our natural predisposition will play a large part in what our potential is in the marathon.   If we have 2 people with the same 10k PR but one has a shorter distance predisposition (person A) and one has a longer distance predisposition (Person B), then Person B will have better potential in the marathon than Person A, and Person A will have greater potential at the 5k than Person B.  This helps explain why Desi Davila and Shalane Flanagan are pretty evenly matched in the marathon but Shalene has a 10k PR more than a minute faster than Desi.   This also helps explain why Dick Beardsley could run even with Alberto Salazar in the marathon when he might have been lapped by Alberto in a track 10k.  Desi and Dick may simply have greater long distance predispositions than Shalane and Alberto.  This doesn’t mean that a person with a longer distance predisposition can’t run very good at shorter races (or vice versa), it just means that their potential is better at the races closer to their predisposition. 

Doing some research and investigation on this subject over the last several years, I have made some general findings.  The typical neutral predisposition distance runner will slow roughly 4.5% each time the distance is doubled (starting at 5k) if they are equally as well prepared for each race distance.   Being neutral means they will fair roughly the same in equally competitive races at different distances.  Their 31:00 10k PR, translates up into 1:08:31 half marathon and 2:23:12 marathon potential and down to 14:50 5k potential if equally as well prepared for each race. 

With 4.5% representing neutral, I find the standard range to be roughly 3.5% (strong long distance predisposition) to 5.5% (strong shorter distance predisposition).   This range can make a big difference in the athlete’s potential at various distances.  If we you use a 31:00 10k as our base time we see that a runner with a strong shorter distance predisposition may only have 2:26:02 marathon potential (slowing 5.5% each time the distance doubles), but a neutral predisposition may have 2:23:12 potential (as given above), and runner with a strong longer distance predisposition may have 2:20:23 potential. 

While there may be a few individuals who fall outside of this 3.5% to 5.5% range, I think the range captures 99% of all serious distance runners.  I break this range down into 5 sub-categories: 

Strong Long Distance Predisposition:   slows roughly 3.5%

Moderate Long Distance Predisposition:  slows roughly 4.0%

Neutral Predisposition:  slows roughly 4.5%

Moderate Short Distance Predisposition:   slows roughly 5.0%

Strong Short Distance Predisposition:  slows roughly 5.5%

My terminology is distance running specific so “short distance” is 3k-5k and “long distance” is the 30k to marathon.

Using our example above (31:00 10k PR) these sub categories produce the following results at various distances: 

	Strong Short Distance	Moderate Short Distance	Neutral	Moderate Long Distance	Strong Long Distance
5k	0:14:42	0:14:46	0:14:50	0:14:54	0:14:58
10k	0:31:00	0:31:00	0:31:00	0:31:00	0:31:00
HM	1:09:13	1:08:52	1:08:31	1:08:10	1:07:49
Mar	2:26:02	2:24:37	2:23:12	2:21:47	2:20:23

We have all seen this, and numerous time recently at an elite level.  You see 2 guys who run roughly the same times in the 10k but when they move up to the marathon there may be 3, 4 or 5 minutes different in their performance.  This doesn’t mean that the coach of the runner who ran slower didn’t necessarily train them as well as the other runner’s coach did, it may simply mean that the faster runner has a greater predisposition to that distance than the other runner.   

It is important to note that all of this assumes the runner is equally as well trained for each distance.  This will not be the case for a lower mileage runner, as 60 miles a week will not allow you to be as well prepared for a marathon as it will for a 5k or 10k.  For this reason it is hard for some recreational or even sub-elites to fully judge their predisposition based strictly on race times. 

Our predispositions are not something that we can influence or change to a great degree, rather it just shows us what distances we are naturally best off focusing on for greatest potential.  This can be very valuable information for a runner and/or coach to have.

For example, when I began coaching Stephanie Pezzullo in late 2011, she was primarily a Steeplechaser and 5k runner, and most in the sport (including Pezz herself) thought of her in that light.  But as I began to coach her and saw her workouts and began to help her explore her range, I noticed that while she had primarily run the shorter distances in the past, she in fact had a neutral predisposition.  This meant that she had the potential to run much faster than she had ever thought of in longer distance races like the half marathon or marathon.  Based on this, in the spring of 2012, I told her I thought it was possible for her to run 2:32-2:33 in a fall marathon if that was of interest to her.  She decided to go for it and she ended up running a 2:32:42 debut in Chicago.  Until we discovered she had a neutral predisposition, the idea of running a 2:32 may not have even occurred to her as an option.

Understanding a runner's predisposition also helps a coach and athlete to understand the approriate paces to use in training.  For example, if I coach 2 runners with 31:00 10k PR's, but one has a moderate long distance predisposition and the other a moderate short distance predisposition, and I send them out to do a 10 mile aerobic threshold (AT) tempo run, the approriate pace will be different for each of them because of their predispositions.   The runner with the moderate shorter distance predisposition will need to do this workout at about 5:30 pace while the runner with the moderate longer distance predisposition can probably handle about 5 seconds per mile faster.  Similarly if we are doing some VO2 Max repeats the runner with the shorter distance predisposition will probably be able to hit slightly better times than the longer distance predispoition runner.  Knowing the runner's predisposition helps in setting expectations and avoid over-training.