The end of 記録，記録的な／記録する-breaking マラソンs? As 走者s 準備する to take to the streets of New York 専門家s say we may have reached the 限界 of human 業績／成果

At the 2016 Rio Olympics, just two running world 記録，記録的な／記録するs were bested―South Africa's Wayde 先頭 Niekerk in the 400-metre men's event and Ethiopia's Almaz Ayana in the women's 10,000m. Pictured is?先頭 Niekerk at the World 運動競技のs 選手権s in London in 2017, competing in the men's 400 メーター final

Only one world 記録，記録的な／記録する was broken at this year's 運動競技のs world 選手権s in London, in the newly-recognised women's 50km race walk.

And at the 2016 Rio Olympics, just two running world 記録，記録的な／記録するs were bested―South Africa's Wayde 先頭 Niekerk in the 400-metre men's event and Ethiopia's Almaz Ayana in the women's 10,000m.

After the 広大な／多数の／重要な 前進するs of the 20th century, 'the 率 of 改良 is approaching 無 for the 大多数 of 運動競技の 裁判，公判s,' said Marc Andy, a 研究員 at フラン's 学校／設ける of Sport Biomedical 研究 and Epidemiology (IRMES).

In 2007, the 学校／設ける analysed the history of Olympic 記録，記録的な／記録するs since the modern Games began in 1896 and calculated that 競技者s have reached 99 パーセント of what is possible within the 限界s of natural human physiology.

The most 最近の 近づく 打開 in the gruelling マラソン occurred in May when Kenya's Eliud Kipchoge （機の）カム agonisingly の近くに to 冒険的な immortality, nearly running the first sub two-hour マラソン.

He 行方不明になるd the mythical 示す by just 25 seconds.

But the race 条件s at the Nike-sponsored event were so favourable―Kipchoge ran behind a six-man pacesetting team and was 追跡するd by a time-keeping 乗り物 on a racing 回路・連盟 in Monza, Italy―that the time was not recognised by the International 協会 of 運動競技のs 連合s (IAAF).

Fellow Kenyan Dennis Kimetto remains the world 記録，記録的な／記録する 支えるもの／所有者 for his 2:02:57 run in 2014.

Imagining the perfect 走者

Coaches and scientists have long tried to 人物／姿／数字 out the optimal 業績／成果 条件s for running the classic マラソン distance of 42.195 kilometres (26.2 miles).

Beyond the ideal 気温―around 12 degrees Celsius (53 degrees Fahrenheit)―and the 走者 存在 small, 'there are dozens of factors at play, from 団体／死体 type to physiological and biomechanical 基準,' said Pierre Sallet, a 業績／成果 専門家 from 競技者s for Transparency, an organisation that 促進するs 正直さ in sport.

'How are we going to identify these parameters in these 部類s? How will we manage 栄養 and 高度 training 同様に as maximising form and energy to arrive on the day in the optimal psychological and physical 条件?' Sallet asked.

Beyond 環境 and 団体／死体 形態／調整, 'three major physiological parameters come into play in マラソンs,' Vincent Pialoux, 副 長，率いる of Lyon's の間の-University 研究室／実験室 of Human Movement Biology, told AFP.

'Endurance, the a bility to create energy using oxygen,' which is 手段d by a 走者's VO2 max (最大限 Oxygen Uptake Capacity), and 'モーター efficiency', the 団体／死体's ability to save energy, Pialoux said.

'Of these three factors, if we take the best data 手段d in the 研究室／実験室 on different 競技者s, we arrive at times 井戸／弁護士席 below the 限界s 予報するd' by models based on the 進化 of 業績／成果, he said.

'Human machine is コンビナート／複合体'

An 競技者 who 連合させるs all the optimal 条件s has yet to be 設立する. When Ethiopia's あられ／賞賛する Gebrselassie broke his own world 記録，記録的な／記録する in Berlin in 2008 he was 35 years old.?

But Pialoux said that VO2 Max 減少（する）s over time.

Within all these very human 強制s, could 麻薬ing be the 進化 the models did not 予報する?

Should we 恐れる the シナリオ imagined by ベルギー philosopher ジーンズ-Noel Missa, in which genetically 高めるd 競技者s compete for 会社／団体s at the 2144 Brussels Olympics?

At the 2016 Rio Olympics, just two running world 記録，記録的な／記録するs were bested―South Africa's Wayde 先頭 Niekerk (pictured) in the 400-metre men's event and Ethiopia's Almaz Ayana (pictured) in the women's 10,000m. Pictured is Ayana during the メダル 儀式 for the women's 10000m final of the Rio 2016 オリンピック

It's not time to panic yet, but Xavier Bigard, 科学の 助言者 to the French Anti-麻薬ing 機関 (AFLD) said there are several 原因（となる）s for 関心, 含むing 演習 pills that could be used '増加する the 影響s of training,' and EPO 麻薬ing, which 増加するs oxygen absorption, 許すing 競技者s to run harder and faster without tiring.

While 茎・取り除く-独房 therapy may sound futuristic, it has already been used in some sports to help 傷をいやす／和解させる 傷害s.

It is genetic 麻薬ing that seems to ぼんやり現れる largest over the 未来 of cheating in sports.

Doctors have for years been 実験ing with ways to 注入する synthetic 遺伝子s into 患者s, altering an individual's genome to 高める muscle 回復 or 茎・取り除く muscle 悪化／低下, の中で other 利益s.

The most 最近の 近づく 記録，記録的な／記録する 打開 in the gruelling マラソン occurred in May when Kenya's Eliud Kipchoge （機の）カム agonisingly の近くに to 冒険的な immortality, nearly running the first sub two-hour マラソン. Pictured is Eliud Kipchoge 反応するing after winning the London マラソン on 24 April 2016

These techniques could hypothetically give 競技者s a 抱擁する advantage.

But 'the 身元 card of a muscle fibre is based on thousands of 遺伝子s, we cannot change them change them all,' said Bigard, 追加するing the 'human machine is very コンビナート／複合体'.

'The 変形 of man into an animal 有能な of running a マラソン in one hour and 40 minutes would take a long time, if it is possible, and there are an incalculable number of 科学の 限界s,' said Sallet.

And, he 追加するd, 'there will always be one 限界: keeping the person alive.'

Dennis Kimetto of Kenya celebrates after crossing the finish line in new world 記録，記録的な／記録する time during the 41th BMW Berlin マラソン on September 28, 2014 in Berlin, Germany.?Dennis Kimetto remains the world 記録，記録的な／記録する 支えるもの／所有者 for his 2:02:57 マラソン run in 2014

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