B1 · Intermediate
12 min
sports sciencehuman physiologyathleticsendurance sports
The Impossible Barrier: The Science of the Two-Hour Marathon
La Barrera Imposible: La Ciencia del Maratón de Dos Horas
This week in London, two runners did something many scientists thought was impossible: finish a marathon in under two hours. Fletcher and Octavio dig into human physiology, sports technology, and what this moment tells us about the limits of the body.
Esta semana en Londres, dos corredores hicieron algo que muchos científicos pensaban que era imposible: terminar un maratón en menos de dos horas. Fletcher y Octavio hablan sobre la fisiología humana, la tecnología deportiva y lo que este momento nos dice sobre los límites del cuerpo.
7 essential B1-level terms from this episode, with translations and example sentences in Spanish.
| Spanish | English | Example |
|---|---|---|
| batir | to beat, to break (a record) | Assefa consiguió batir su propio récord mundial en Londres. |
| glucógeno | glycogen | Cuando el glucógeno se termina, el corredor pierde energía rápidamente. |
| rendimiento | performance, yield | Las zapatillas nuevas mejoraron el rendimiento de los atletas. |
| superar | to surpass, to overcome | Los dos corredores lograron superar la barrera de las dos horas. |
| altitud | altitude | Los corredores kenianos se entrenan a gran altitud desde pequeños. |
| glóbulos rojos | red blood cells | Vivir a gran altitud aumenta la cantidad de glóbulos rojos en la sangre. |
| ritmo | pace, rhythm | Es importante mantener un ritmo constante durante todo el maratón. |
Two hours.
For decades, scientists argued about whether a human being could run 26.2 miles in under two hours.
This morning in London, two of them did it.
Sí, y fue increíble.
Yes, and it was incredible.
Sabastian Sawe terminó en una hora, cincuenta y nueve minutos y treinta segundos.
Sabastian Sawe finished in one hour, fifty-nine minutes and thirty seconds.
El récord mundial oficial.
The official world record.
Yomif Kejelcha también terminó en menos de dos horas, pocos segundos después.
Yomif Kejelcha also finished in under two hours, just seconds later.
And the women's record fell too.
Tigst Assefa ran 2:15:41.
Three world records in one race, in one city, on one Sunday morning.
That's almost hard to process.
Pero hay que hablar del contexto.
But we need to talk about the context.
Eliud Kipchoge, el corredor keniano, ya corrió un maratón en menos de dos horas en 2019, en Viena.
Eliud Kipchoge, the Kenyan runner, already ran a marathon in under two hours in 2019, in Vienna.
Terminó en una hora, cincuenta y nueve minutos y cuarenta segundos.
He finished in one hour, fifty-nine minutes and forty seconds.
Right, but Kipchoge's run in Vienna didn't count as an official world record.
The conditions were completely controlled.
Rotating pacers, a laser guiding him on the road, essentially a laboratory experiment disguised as a race.
Exactamente.
Exactly.
El maratón de Londres es una carrera oficial.
The London Marathon is an official race.
Hay competición real, hay reglas estrictas.
There is real competition, there are strict rules.
Por eso este récord es diferente y más importante para la ciencia.
That's why this record is different and more important for science.
Let me ask you something.
When I was covering the Athens Olympics in 2004, I interviewed a physiologist who told me flatly that sub-two hours was biologically impossible in a fair race.
What changed?
Muchas cosas.
Many things.
Pero primero, hay que entender cómo funciona el cuerpo humano cuando corre un maratón.
But first, we need to understand how the human body works when running a marathon.
El problema principal es la energía.
The main problem is energy.
El cuerpo tiene dos fuentes: el glucógeno y la grasa.
The body has two sources: glycogen and fat.
Glycogen being the fuel stored in the muscles, basically.
And the classic marathon problem is that you run out of it around mile twenty.
That's 'the wall.'
Correcto.
Correct.
Cuando el glucógeno se termina, el cuerpo usa la grasa, pero quemar grasa es mucho más lento.
When glycogen runs out, the body uses fat, but burning fat is much slower.
Y a esa velocidad, si el corredor depende de la grasa, no puede mantener el ritmo necesario para terminar en dos horas.
And at that speed, if the runner depends on fat, they cannot maintain the pace needed to finish in two hours.
So one piece of this is nutrition science.
Elite runners now consume gels during the race, precise carbohydrate loading, timing everything down to the minute.
It's not just running anymore, it's fuel management.
Sí, y también hay otro concepto muy importante: el VO2 máximo.
Yes, and there is also another very important concept: VO2 max.
Es la cantidad máxima de oxígeno que el cuerpo puede usar cuando hace ejercicio intenso.
It is the maximum amount of oxygen the body can use during intense exercise.
Los mejores maratonistas tienen un VO2 máximo muy alto.
The best marathon runners have a very high VO2 max.
And this is partly genetic.
Runners from the East African highlands, Ethiopia, Kenya, they tend to have naturally higher aerobic capacity.
There's also the altitude effect.
Growing up at 2,000 meters does something to your blood.
Exacto.
Exactly.
A mayor altitud, hay menos oxígeno en el aire.
At higher altitude, there is less oxygen in the air.
El cuerpo responde produciendo más glóbulos rojos.
The body responds by producing more red blood cells.
Cuando estos corredores bajan a nivel del mar, tienen más glóbulos rojos que la mayoría de las personas.
When these runners come down to sea level, they have more red blood cells than most people.
Eso es una ventaja enorme.
That is an enormous advantage.
More red blood cells means more oxygen delivered to the muscles per breath.
Which is why altitude training camps became standard for elite distance runners decades ago.
But Sawe and Kejelcha aren't just products of altitude.
There's also what's on their feet.
Las zapatillas.
The shoes.
Este es un tema muy interesante y también muy controvertido.
This is a very interesting topic and also very controversial.
En los últimos diez años, la tecnología de las zapatillas cambió completamente.
In the last ten years, shoe technology changed completely.
Ahora tienen placas de fibra de carbono dentro.
Now they have carbon fiber plates inside.
Nike's Vaporfly started this whole argument.
The carbon plate acts like a spring, storing energy with each stride and returning it.
Studies showed runners were something like four percent more efficient wearing them.
Four percent is a staggering number in elite sport.
Y hubo un debate grande: ¿es justo?
And there was a big debate: is it fair?
¿Son las zapatillas una forma de trampa tecnológica?
Are the shoes a form of technological cheating?
World Athletics, la organización internacional, decidió que no, pero puso límites en el grosor de la suela.
World Athletics, the international organization, decided no, but put limits on the thickness of the sole.
Which opens a fascinating question about where sport ends and engineering begins.
I mean, competitive cyclists have been through this for decades with bikes.
Swimming had the polyurethane suit controversy in 2008.
Technology and the human body keep colliding.
Es verdad.
It's true.
Pero hay algo más que cambió: el conocimiento sobre el entrenamiento.
But there is something else that changed: knowledge about training.
Antes, los corredores hacían mucho volumen, muchos kilómetros cada semana.
Before, runners did a lot of volume, many kilometers each week.
Ahora el entrenamiento es más inteligente, más científico.
Now training is smarter, more scientific.
What does that look like in practice?
Because from the outside, elite marathon training still sounds absolutely brutal.
Sí, todavía es muy duro.
Yes, it is still very hard.
Pero ahora los entrenadores usan datos.
But now coaches use data.
Usan sensores para medir el ritmo cardíaco, la temperatura del cuerpo, la forma de correr.
They use sensors to measure heart rate, body temperature, running form.
Saben exactamente cuándo el corredor debe descansar y cuándo puede trabajar más.
They know exactly when the runner should rest and when they can work harder.
There's also the biomechanics side.
Running economy, they call it.
Essentially, how efficiently does your body convert energy into forward motion?
Two runners with identical VO2 max can perform completely differently based on their stride mechanics.
Sí.
Yes.
La posición del cuerpo, el ángulo de los pies, cómo aterriza el pie en el suelo.
The position of the body, the angle of the feet, how the foot lands on the ground.
Todo importa.
Everything matters.
Los mejores corredores del mundo tienen una forma muy eficiente y muy natural.
The best runners in the world have a very efficient and very natural form.
No pierden energía con movimientos innecesarios.
They do not waste energy with unnecessary movements.
Now, I want to talk about the mental piece, because I think it gets underestimated.
Kipchoge said something years ago that stuck with me.
He said the barrier wasn't physical.
It was in people's heads.
Esto es muy interesante.
This is very interesting.
Es como el caso de Roger Bannister y la milla de cuatro minutos.
It is like the case of Roger Bannister and the four-minute mile.
Durante años, los científicos decían que correr una milla en menos de cuatro minutos era imposible para el cuerpo humano.
For years, scientists said running a mile in under four minutes was impossible for the human body.
Bannister lo hizo en 1954.
Bannister did it in 1954.
Y después, muchos otros lo hicieron también.
And afterwards, many others did it too.
Within six weeks, John Landy broke Bannister's record.
The physical barrier didn't move, but the psychological one collapsed.
And now we may be watching the same thing happen with the marathon.
The question is, how low can this go?
Los científicos discuten mucho sobre este tema.
Scientists debate a lot about this topic.
Algunos piensan que el límite teórico para un hombre es aproximadamente una hora y cincuenta y ocho minutos.
Some think the theoretical limit for a man is approximately one hour and fifty-eight minutes.
Otros dicen que es imposible saber el límite con exactitud.
Others say it is impossible to know the limit exactly.
Because the human body isn't a fixed machine.
We keep discovering it has more capacity than we thought.
That's true in sport, but also in medicine, in aging research.
People are living longer and running marathons into their seventies.
Y no podemos olvidar a las mujeres.
And we cannot forget the women.
Tigst Assefa corrió dos horas, quince minutos y cuarenta y un segundos.
Tigst Assefa ran two hours, fifteen minutes and forty-one seconds.
Esto es extraordinario.
This is extraordinary.
El récord anterior era de Assefa también, dos horas y dieciséis minutos, del Maratón de Berlín en 2023.
The previous record was also Assefa's, two hours and sixteen minutes, from the Berlin Marathon in 2023.
She broke her own record.
[gasp] And there's a genuinely fascinating piece of physiology here.
Women's marathon times have been improving faster than men's over the last forty years.
Some researchers think women may be physiologically better suited for ultra-long distances.
Sí.
Yes.
El cuerpo femenino usa la grasa como combustible de manera más eficiente.
The female body uses fat as fuel more efficiently.
Esto es una ventaja en carreras muy largas.
This is an advantage in very long races.
Y también, las mujeres generalmente tienen un ritmo más estable durante la carrera.
And also, women generally have a more consistent pace during the race.
No empiezan tan rápido y después se cansan tanto.
They do not start as fast and then get as tired.
Which is actually good racing strategy for anyone, but apparently easier to execute physiologically for women.
The question of whether the women's record will ever approach the men's is one of the more contested debates in sports science.
Lo que sí podemos decir es que este momento en Londres fue histórico para los dos.
What we can say is that this moment in London was historic for both.
Para los hombres y para las mujeres.
For men and for women.
Es un día importante para el atletismo y también para la ciencia humana.
It is an important day for athletics and also for human science.
And London itself matters here.
The course is flat, the crowd is enormous, the organization is extraordinary.
There's a reason world records keep falling there.
It's almost engineered for fast times.
Exacto.
Exactly.
Y el público ayuda mucho.
And the crowd helps a lot.
Cuando un corredor está muy cansado en el kilómetro treinta y cinco, escuchar miles de personas que gritan su nombre puede cambiar todo.
When a runner is very tired at kilometer thirty-five, hearing thousands of people shouting their name can change everything.
Esto también es ciencia, la ciencia de la motivación.
This is also science, the science of motivation.
The crowd as a physiological variable.
That's a genuinely interesting frame.
Noise reduces perceived exertion, there's actual research on this.
Your brain processes the signal differently when there's external stimulation.
Oye, Fletcher, quiero preguntarte algo.
Hey, Fletcher, I want to ask you something.
¿Tú corriste algún maratón en tu vida?
Did you ever run a marathon in your life?
I ran a half marathon in Buenos Aires once in 2003, finished in two hours and four minutes, felt like I'd crossed the Sahara barefoot, and swore never again.
Sawe just ran twice that distance in less time.
I find that genuinely upsetting.
Sí, pero tú no tienes un VO2 máximo de ochenta y cinco.
Yes, but you don't have a VO2 max of eighty-five.
[chuckle] Tampoco yo.
Neither do I.
Somos personas normales.
We are normal people.
Pero es bonito saber que el cuerpo humano puede hacer cosas extraordinarias.
But it is beautiful to know that the human body can do extraordinary things.
Speaking of extraordinary things, I want to ask you about a phrase you used a few minutes ago.
You said 'batir un récord.' I know that verb from other contexts but I wasn't sure I'd ever heard it applied to sport quite that way.
Sí, es una expresión muy común en español.
Yes, it is a very common expression in Spanish.
'Batir un récord' significa romper un récord, superarlo.
'Batir un récord' means to break a record, to surpass it.
Pero también puedes decir 'romper un récord' o 'superar un récord.' Los tres son correctos, pero 'batir' es el más natural en el contexto del deporte.
But you can also say 'romper un récord' or 'superar un récord.' All three are correct, but 'batir' is the most natural in a sporting context.
So 'batir' is the sporting verb.
What else can you bat?
Can you 'batir' something that isn't a record?
Sí.
Yes.
'Batir' tiene otros significados también.
'Batir' has other meanings too.
Puedes batir huevos en la cocina, como en inglés 'to beat eggs.' Y también puedes batir a un enemigo, significa derrotarlo.
You can beat eggs in the kitchen, like in English 'to beat eggs.' And you can also 'batir' an enemy, meaning to defeat them.
El verbo tiene diferentes usos según el contexto.
The verb has different uses depending on the context.
So the same root for eggs in the kitchen and world records in London.
That's the kind of thing that makes a language feel alive.
In English we use 'beat' the same way, actually.
You beat a record, you beat eggs, you beat an opponent.
Exacto, hay un paralelo directo.
Exactly, there is a direct parallel.
Y si quieres sonar natural en español cuando hablas de deporte, recuerda: 'batir el récord.' No 'hacer' el récord, no 'ganar' el récord.
And if you want to sound natural in Spanish when talking about sport, remember: 'batir el récord.' Not 'hacer' the record, not 'ganar' the record.
Esos dos suenan mal.
Those two sound wrong.
'Batir' es la palabra correcta.
'Batir' is the right word.
Filed.
Right next to 'embarazado,' which I will never misuse again in my life.
Thanks for this one, Octavio.
A historic day in London, extraordinary science, and one very useful verb.
De nada.
You're welcome.
Y la próxima vez que corras un medio maratón, Fletcher, intenta batir tu récord de Buenos Aires.
And the next time you run a half marathon, Fletcher, try to beat your Buenos Aires record.
Tienes veinte años más de experiencia.
You have twenty more years of experience.