Marathon time can be shortened by good use of pacemakers

This article came up on Nikkei Asian Review the other day.

With the title “Marathon time can be shortened by good use of pacemakers”.
The article details Yuki Kawauchi’s record two sub 2:10 marathons within two weeks and how the world’s elite marathon runners make use of pace makers throughout part of the race and some theories on his biomechanics.

How air resistance is reduced?
The writer puts the question to mechanical engineering professor, Shinichiro Ito of Kogakuin University.

The role of pace makers has changed to being wind breakers for runners seeking records.
In this year’s Berlin Marathon (September), Wilson Kipsang Kiprotich (Kenya) broke the long standing marathon world record (2:03:23) formerly held by Patrick Makau Musyoki (Kenya) (2:03:38) set in 2011. In both these races, the record holders were not in the lead pack until later in the race.

In the past, the main role of pacemakers has been to maintain a particular race pace until recently where they now also function as providers of a slip stream.

With the use of fixed models (dolls) research was conducted.

The findings were that a single runner has the drag coefficient of 0.97, air resistance is reduced to 0.11 when sandwiched between a two other runners (one in front and behind). The runner third inline will have drag coefficient of 0.3, greater than that of the second runner.

singlerunner3inrow

Maximum slipstream when running behind a row of three.
When Naoko Takahashi broke the women’s marathon record (also at Berlin in 2001, 2:19:46), she ran in a pack of five, with four male runners (front, rear, left and right) to be the first female to go sub 2:20. In this configuration she would have had a drag coefficient of 0.31.

The research continues to test a pack of four runners, with 3 of the runners running alongside each other. Forming a first row “wall”, the fourth runner tucked in behind the middle runner of the row will have a drag coefficient of 0.07 (less than 10% of running alone).

wallof3

Although drag is ultimately reduced using three pace makers, three inline configuration is probably the most beneficial in terms of cost/performance.

A 175cm runner with the ability to run 2:10, sandwiched between two other runners at 2:05 pace up to the 35km IAAF convention will spare about 77kcal. This is equivalent to about 1360m or approximately 4 minutes.

Professor Ito concludes that “rather than run blindly for a record time, a runner being properly positioned behind a pacemaker(s), making use of the slipstream, will have an overwhelming advantage”.

Use of the spring of the achilles tendon recommended.
With regards to running form: “Kicking the ground, extending the ankle after foot landing is not good. Although this method of running is effective, it is only if each step is timed correctly over the entire 42.195km – which is impossible, causing a loss when timing isn’t correct.”.

Although some older Japanese coaches, still teach this method, Ito discourages it and it is better to run using the spring of the achillies tendon with the knee and ankle at fixed angles.

Thin (small) calves of the elite runners.
When looking at photos of Kiprotich and Makau, they both feature very thin calves.
World record holder and olympic gold medalist for the men’s 100m and 200m Usain Bolt (Jamaica) also has thin calves. Both elite sprinters and long distance runners share this feature. Sharing the same principles as when comparing the ease of swinging a fatter bat (baseball) against a thinner bat, it is easier to move the section below the knee.

“Kawauchi’s calves have been getting fatter through training..possibly because he is running with the image of kicking the ground. Stopping this style of running may help reduce calf muscles size possibly allowing Kawauchi to achieve better times”.

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