2019-10-19_New_Scientist

19 October 2019 | New Scientist | 7

TWO years after missing out

on a 2-hour marathon by only

25 seconds, Eliud Kipchoge

has become the first person

ever to run 42.2 kilometres in

less than 2 hours.

He ended the run in Vienna,

Austria, on 12 October, smiling

and pointing to the crowd as he

accelerated through the final

kilometre to finish in 1:59:40.

The feat won’t be recognised as

an official world marathon record

because it wasn’t a race and the

elite athlete was assisted by a

pace car and a rotating team of

41 pacemakers.

Nevertheless, Kipchoge’s

achievement is undoubtedly

historic. And the following day,

Brigid Kosgei set a women’s

world marathon record of 2:14:

in the Chicago Marathon.

These feats show how far sports

science has come. “Many of the

leading scientists didn’t really

see [a sub-2-hour marathon]

happening in the next couple

of years,” says Stephen Mears at

Loughborough University, UK.

The marathon record was just

under 3 hours at the start of the

20th century, but it quickly fell

in the following decades due

to improvements in technology,

training and nutrition, says

Mears. Roger Bannister broke the

4-minute mile in part because of

interval training, for example.

There have been other

developments too, such as a

growing grasp of the role our

minds play in capping athletic

performance.

Mears describes Kipchoge as

a “once-in-a-lifetime athlete”. He

probably has superb VO 2 max – the

maximum amount of oxygen the

body can utilise – and exceptional

running economy, meaning he

uses energy extremely efficiently.

Kipchoge’s second effort at

sub-2-hours involved small

improvements to many different

aspects of the race, says Mears. The

formation of pacers around him

was precisely tweaked and the car

was slightly further ahead than

before. The drinking strategy was

different, the weather better, the

course flatter, his shoes slightly

modified – and this time there

was a supporting crowd. ❚

Eliud Kipchoge’s historic sub-2-hour marathon comes years ahead

of sport scientists’ predictions, reports Adam Vaughan

Pregnancy

Pollution linked to

miscarriage risk

HIGH levels of air pollution

may increase the chance

of a missed miscarriage,

according to data from

pregnant women living and

working in Beijing, China.

A missed or silent

miscarriage is when a fetus

dies or stops developing

during pregnancy, usually

without any symptoms. Such

miscarriages tend to happen

in the first trimester, and can

be picked up on 12-week

scans. Little is known about

what causes them.

Liqiang Zhang at Beijing

Normal University and his

colleagues assessed the

health records of 17,

women in Beijing who had

a missed miscarriage in

their first trimester. They

also collected data on the

levels of air pollutants close

to where the women lived

and worked.

Those exposed to higher

levels of air pollution had

an increased risk of a missed

miscarriage. The team didn’t

directly test if the link was

causal, but there is growing

evidence that air pollutants

can reach and potentially

harm a developing fetus

(Nature Sustainability,

doi. org/dcnh).

Zhang’s team also

found that, since China’s

government issued rules

to reduce pollution in 2013,

air pollutant levels have

declined, as has the risk

of missed miscarriage. ❚

Marathon milestone

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