The science behind the sub two-hour marathon


In Vienna, October 2019, Eliud Kipchoge did the unthinkable. He broke the two-hour marathon barrier with a time of 1:59:40 for the 42.195km.

Once considered a physiological impossibility, the fastest marathon now stands at sub-two hours. Even if it isn’t recognised as a new world record by the IAAF partly due to use of pacemakers, Kipchoge has undoubtedly completed a feat some deemed unimaginable.

But how much of that relied upon state-of-the-art trainers, or 41 of the world’s best elite runners as pacemakers, or even genetics?

Kipchoge has previously attempted to break the sub two-hour barrier with times clocking in at 2:01:39 at the Berlin marathon in 2018 and 2:00:25 at the Monza racing track in 2017. Sponsored by the Ineos Sub2 programme, Kipchoge never ran slower than a terrifying pace of 2:52 minutes per km to cement himself in the history of athletics. He ran the first 5km in 14:10, with an overall marathon pace that only 5 out of 51,363,611 5km parkruns have been faster than, according to a tweet by Ian Rutson on the day. For even more context, the average 5km in the UK is completed in 33:54 minutes according to Runners World.

Kipchoge never ran slower than 2:52 min/km

Whilst being a marathon runner relies a lot on determination and self-motivation, physiology can hamper the best of athletes, allowing them only to progress so far. The maximum oxygen consumption is one of the most important factors determining a runner’s power. VO2 max is the maximum volume of oxygen per unit of body weight an athlete can use in a minute. Elite marathon runners use around 80% of the maximum, with high intensity training contributing to this. But eventually genetics gets the final say, limiting the oxygen usage through lower haemoglobin levels or fewer red blood cells.

Even when you’re not running at a chatting pace running is inefficient, with most of the power generated swallowed by the ground. Only around 45% of your leg power moves you forwards. So, does that mean there’s a gap in the market for springy shoes? Nike are heading for production of shoes that will allow more efficient energy transfer through soles made of a type of foam to reduce energy wastage. Indeed, Kipchoge wore a prototype Nike trainer with added airbags and carbon fibre plates making them more efficient than the ones he wore for the Sub2 attempt in 2017, where the trainers worn were supposed to increase running efficiency by a whopping 5%.

Physiology can hamper the best of athletes

The controversial pacemakers reduced wind resistance and kept Kipchoge on track for the sub two-hour goal. Not to mention the car ahead of the runners displaying a laser on the road of the 2:50 min/km pace needed and ideal running weather conditions for an entirely flat course that was 90% straight. Vienna’s low altitude, lack of rain and a temperature of around 10°C meant that Kipchoge wasn’t hampered by anything he couldn’t control, and it was down to him.

Then there was the carb-loading. “Eat pasta, run faster” isn’t a phrase for nothing, but Kipchoge’s choice of carbohydrate came in the form of powdered drinks handed to him by cyclists throughout the race. Another reason the world record didn’t count as one.

Despite IAAF not recognising the sub two hour marathon, Kipchoge holds the world record at 2:01:39 and has paved the way for a whole host of runners to defy the two hour marathon barrier like he did.

Image by Marco Verch via Flickr and Creative Commons

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