Yesterday Wilson Kipsang took 15 seconds off the marathon world record, running 2:03:23. It triggered, as it always does, talk of how close they are to breaking the two-hour barrier. But that's very, very premature. For reasons of physiology, performance evolution, and the inter-connectedness of performances from 10km to the marathon, we are a long, long way from going under two hours.
It's not the same as for you or I, who find ourselves a few minutes outside a barrier, and know that six months of hard training and a good day will break it. This is a world where the margins are tiny - that's why we can look at the pacing strategy and the splits and comment that perhaps it was a little too fast in sections, when in reality, "too fast" means 1 second per kilometer, accumulated over 20 minutes! The precision of the physiology to run a 2:03 is extra-ordinary.
So consider for instance the progression. In the modern era, catalyzed by da Costa's breaking of Dinsamo's 1988 record, the improvements in the record are as follows:
23 seconds, 4 seconds, 43 seconds, 29 seconds, 27 seconds, 21 seconds, 15 seconds.
This record is not going to be "smashed" by anyone. Anything greater than 20 seconds is a big improvement.
The real story is not how often the record is broken, it's how often it isn't
What the sequence above doesn't say, which is more important, is that for every successful attempt, there are probably fifty (a hundred?) unsuccessful ones, where the best runners in the world are on course for the time, for some of the race, then fall away. Every year, five or six big city marathons start with high hopes - London, Dubai, Chicago, Rotterdam, Frankfurt, Berlin and perhaps two or three others. Across these races, there are likely twenty "viable candidates", and yet perhaps one in a hundred will come off, despite intent and incentive.
That's why when you look at the record books, you'll see that there are now about 50 performances under 2:06. Most of those started out as record attempts, and many will have had high hopes up to halfway, or even 30km. In London earlier this year, about six of the best marathon runners in history went to 25km on course for the world record. The explosion was huge, and some ended up finishing outside 2:09, or not at all. I recall Emmanuel Mutai closing at 5:00/km. The same happens every year in many races. Even in Berlin yesterday, only one man of a group of three sub-2:06 guys held on to run a 61:51 second half. Incredible running, but it should highlight just how rare successful attempts are.
The implications - many factors have to align
In the future, that will become more the case. As this record drops, it will become more difficult to break, and that has some implications.
First, it requires an absolutely perfect day. London, where the final 8km are run along the embankment, often finds a headwind that could easily cost 2 sec/km and that would be enough to eliminate record possibilities. Chicago has found itself too hot or too cold. Berlin was too wet recently. Dubai hot or windy. Unless the weather is close to perfect, the record is becoming too strong to break.
Second, the marathon course must be perfect. I think there are probably only four or five courses in the world that are viable for a world record. Dubai, Berlin (obviously), London (though the wind, and the number of turns, makes me wonder whether this is still the case, actually), Chicago, and then one or two of the second tier races like Frankfurt where Kipsang ran 2:03:42 a few years ago.
The marathon course is nothing without the best athletes, and so now you also need huge money to attract the best men, in the right numbers, for a record. London has in the past been so strong that the athletes watch one another rather than risk losing to chase times. New York gets amazing fields, but the course compromises the final time. Second-tier marathons with perfect profiles can't get the depth of quality to deliver the record.
The problem then is that there are only a few opportunities a year for the top guys to have a realistic shot. Now the above three factors need to come together - you need perfect weather on the perfect course, with the best athlete in close to perfect condition, and suddenly you can see why unsuccessful attempts outnumber successful ones so convincingly.
So, what does this mean? It means that if the record is broken by 15 seconds each time (I think this is a realistic expectation, particularly as it gets stronger), then one can expect it to happen perhaps once every three years. More likely four or five in the future, but if it were three, then in order to cut another 3:23 off in 15 second intervals, you're looking at around 40 years.
The physiology and performance links behind the 2-hour marathon
So this talk of a sub-2 hour marathon is so premature. There are a few physiological reasons why it is also not feasible at this stage. I have written on this extensively before:
- The physiological implications of a sub-2 - economy, max and limits
- The pacing-performance implications of a sub-2. Why it's not on the horizon
And that can be taken one step further, to 10km. If you are going to see a 57:x half marathon, then you should also be seeing a 10km that is substantially faster than the current 26:x. The 10km performance required to run a 57 is probably in the high 25s.
It's possible, of course, that the change could come from the ability to sustain high speeds, rather than to nudge the entire system faster. In other words, the runners of the future could well run at current 21km paces for twice the distance without the paces for shorter distances changing. That would change the relationship between intensity and duration as we know it, but it is possible if the threshold capacity of runners changes (substantially) in the future. But that's not going to come instantly - there are physiological barriers that must be inched out of the way, not leapt right over.
Those relate to the physiological implications, which I have written on before, so I won't go into here.
Bottom line is that talking about a sub-2 hour performance after seeing a 2:03:38 improve to a 2:03:23 is just not feasible. The next barrier is 2:03, and I'm sure will go within five years. Then we can begin to work towards 2:02, which will take another ten years, perhaps.
It's a great period for marathon running - every season, fall and spring, we get to anticipate a record at least twice. 2013 has delivered a successful attempt, but it shouldn't lull us into expectation that more of the same is just around the corner.