A deluge of world records have been posted in 2019. We highlight five (well, okay, seven) of the best during an unforgettable calendar year for the sport.
&nbsp;
<h3>Samuel Tefera</h3>
Indoor 1500m
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Samuel Tefera wins the 1500m at the IAAF World Indoor Tour meeting in Birmingham</div>
&nbsp;
The Ethiopian teenager produced a sensational performance to trim 0.14 from Hicham El Guerrouj&rsquo;s 22-year-old world indoor 1500m in Birmingham.
At the same British venue where Tefera was crowned world indoor 1500m champion 11 months earlier, pacemakers Bram Som went through 400m in 55.69 and Jordan Williamsz hit the 1000m mark in 2:21.27.
Tefera kicked past his compatriot Yomif Kejelcha at the bell and raced on to history, recording a stunning time of 3:31.04.
<h3> Julien Wanders</h3>
Road 5km
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Julien Wanders clocks 13:29 in Monaco</div>
&nbsp;
Less than 18 hours after Tefera&rsquo;s blistering performance in Birmingham, Som returned to pace a second world record in successive days, helping Julien Wanders set a road 5km mark of 13:29 at the Herculis 5km.
On the streets of Monaco, the Kenya-based Swiss athlete survived an untimely bout of flu in the lead up to the event to shave one second from Bernard Kibet&rsquo;s pending inaugural world record mark. The 5km road distance was introduced as a world record event in November 2017.
&ldquo;I was a bit worried because I knew 13:30 was the old record and at the finish I saw 13:30,&rdquo; said Wanders. &ldquo;But then then they told me, &lsquo;no, it was 13:29&rsquo;, so I was very happy.&rdquo;
<h3> USA</h3>
Mixed 4x400m relay 
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Mixed 4x400m relay team members Wilbert London, Allyson Felix, Courtney Okolo, and Michael Cherry at the IAAF World Athletics Championships Doha 2019</div>
&nbsp;
Remarkably, the USA smashed the mixed 4x400m world record twice in as many days at the World Athletics Championships in Doha with entirely different quartets.
In the heats, Tyrell Richard, Jessica Beard, Jasmine Blocker and Obi Igbokwe posted a world record time of 3:12.42 in the fledgling event. Then in the final, the team of Wil London, Allyson Felix, Courtney Okolo and Michael Cherry blitzed around the four-lap distance in a benchmark 3:09.34 to grab gold ahead of Jamaica.
The performance also secured Felix, the second leg runner, a record-breaking 12th world title.
<h3> Dalilah Muhammad</h3>
400m hurdles
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Dalilah Muhammad in the 400m hurdles at the IAAF World Athletics Championships Doha 2019</div>
&nbsp;
The Olympic champion set not one but two world 400m hurdles records to take the event to a new realm.
The 29-year-old sliced 0.14 from the 16-year-old world record to record 52.20 at the US Championships in Des Moines before running even faster in Doha. In one of the highlights of the World Championships, the New York native blasted around the 400m oval in 52.16 to hold off her charging 20-year-old US teammate Sydney McLaughlin by just 0.07 to strike gold.
&ldquo;This means so much,&rdquo; she said in the wake of winning world gold and setting a world record. &ldquo;It&rsquo;s difficult to describe. I just wanted the world title so much but to break the world record again is fantastic.&rdquo;
<h3> Brigid Kosgei</h3>
Marathon
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Brigid Kosgei wins the Chicago Marathon</div>
&nbsp;
On an iconic weekend for road running, the Kenyan marathon runner dismantled Paula Radcliffe&rsquo;s 16-year-old world record by a staggering 81 seconds with a dazzling performance on the streets of Chicago.
The 25-year-old defending champion had triumphed at April&rsquo;s London Marathon in a PB of 2:18:20 but few would have predicted a performance of this magnitude.
Hitting the halfway mark in 1:06:59 suggested a finishing time of about 2:14 &ndash; and she went on to deliver, stopping the clock in a breath-taking 2:14:04 to erase the longest standing marathon world record in the modern era.
The previous day in Vienna, Eliud Kipchoge had made history by becoming the first person in history to cover the marathon distance within two hours, albeit in an unratified race.
 Steve Landells for World Athletics

A deluge of world records have been posted in 2019. We highlight five (well, okay, seven) of the best during an unforgettable calendar year for the sport. 

Fab five: world records set in 2019

Julien Wanders has broken world and European records on the roads, but he has learned many valuable lessons along the way, as he outlines here with a letter to his younger self.
&nbsp;
Hi Julien,
Outside of the classroom, do you think of anything else other than sport? You are one sport-crazy kid and I know that you already have a burning desire to one day become a sportsman. You are just not quite sure yet which sport.
You are a handy tennis player and one of your heroes is the Swiss great, Roger Federer. You are also showing good potential on the soccer field, and I believe the regional team are showing an interest in your skills. Meanwhile, you are also a promising runner; good enough to finish inside the top 20 for your age group at the Swiss Cross Country Championships. You are very lucky to have a few options from which you can fulfil your future ambitions.
There is certainly no need to select your sport just yet, Julien. I would advise you to just keep on enjoying and devoting your energy to a range of sports. A combination of your talent and determination will set you on the right path later down the track.
If we stick with athletics for the moment, you are quite the all-rounder. I like the fact you are prepared to sample all events; the long jump, javelin, the middle distances. Nothing is off limits. This is good. Trying out many disciplines will help improve your coordination and build your strength for the future.
Oh, and don&rsquo;t be too concerned by the fact that there is one boy at the club better than you over the middle distances. &nbsp;That boy already has a personal coach and he trains every day. Be patient, Julien. Over time you will defeat him. He will lose motivation and drop out of the sport while you will go from strength to strength.
Music is an important part of family life. Your mum and dad are accomplished musicians, so you had no choice; you had to play an instrument and you opted for the cello. Music practise is not always easy. It can sometimes feel like a chore and you have put in a lot of hard work trying to master the cello. This has taught you the value of self-discipline; a skill that will prove so important in your future running career.
I know this may be hard to read, but occasionally you are prone to acting like a spoilt brat! Remember those times at Christmas when your sister received four presents from your parents and you complained when receiving three? Well, later down the road you will relocate to live and train in Kenya and this will give you a totally different perspective. It will make you less self-centred.
You will see that children in Kenyan come from a very humble background. They have no toys to play with but are happy and content. The experience will change your philosophy on life and you will become a better person.
I don&rsquo;t want to say too much more, Julien. Just keep doing what you are doing and everything will turn out fine.
Julien
 Steve Landells for the IAAF

Julien Wanders has broken world and European records on the roads, but he has learned many valuable lessons along the way, as he outlines here with a letter to his younger self.

Advice to my younger self: Julien Wanders

The following world records have been ratified...
<h3> World records</h3>
Men&rsquo;s 5km: 13:29 Julien Wanders (SUI) Monaco 17 February 2019 Previous: none; new world record event
Women&rsquo;s 5km: 14:44 Sifan Hassan (NED) Monaco 17 February 2019 Previous: none; new world record event
<h3> World U20 indoor record</h3>
Women&rsquo;s high jump: 1.99m Yaroslava Mahuchikh (UKR) Hustopeče 26 January 2019 Equalled: 1.99m Vashti Cunningham (USA) Portland 12 March 2016
 IAAF

The following world records have been ratified...

World records ratified

Dutch champion Sifan Hassan and Swiss contender Julien Wanders set world 5km records* within minutes of each other during the Herculis 5km race along the Monaco coastline on Sunday (17).
Both athletes had set themselves for attempts on the newly-established 5km road standards and they duly delivered on a picture-perfect winter day in Monaco.
The elite women started first from Port Herculis and Hassan&rsquo;s intentions were immediately clear.
The European 5000m champion surged to the front of the field behind the pace-makers, gapping the rest of the field by the time she reached the end of the port. She returned alone to cross the finish line in 14:44, bettering both the pending women&rsquo;s-only race world record of 15:48 and the pending mixed race standard of 14:48. Britain&rsquo;s Laura Weightman finished second in 15:29.
"After 3km I was slow and I thought, 'I&rsquo;m not going to make it'," Hassan said. 
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Sifan Hassan on the way to her 5km world record in Monaco</div>
&nbsp;
&ldquo;I really gave up and was just running, but I pushed at the end, I really sprinted the last 200 metres, and I&rsquo;m so happy. It&rsquo;s my first world record.&rdquo;
&ldquo;When I did the half-marathon last year (she set the European record in Copenhagen last September), that was my 5km best, 15-something. But my training and endurance was good and I thought I could run about 14:45.&rdquo;
The elite men began five minutes later and Wanders, who broke Mo Farah&rsquo;s European half-marathon record last week, continued to show outstanding form, completing his 5km in 13:29, just one second inside the target time of 13:30, and eight seconds clear of second-placed Sondre Moen of Norway (13:37).
When Wanders crossed the finish line, he was unsure if he had done enough to claim his first world record but he was delighted when his official time was confirmed.
&ldquo;I got two European records and now a world record, my first one, so it&rsquo;s amazing,&rsquo;&rsquo; Wanders said.
The 22-year-old Kenya-based runner revealed that he had battled some illness in the days leading into the race and was uncertain if it would detract from his performance.
&ldquo;I was confident. The only thing was I got flu three days ago so it was a challenge for me, I was not sure," he said.
&ldquo;I wanted to go for around 13:20 and we were right on pace at half way but then we were losing time and I was a bit worried because I knew 13:30 was the old record and at the finish, I saw 13:30 and then they told me, no, it was 13:29, so I was very happy.&rdquo;
Both athletes finished their road-racing campaigns today and will now pursue other ambitions for the rest of the year.
"Now I will focus on the track and I hope to do well in Doha (at the IAAF World Athletics Championships in September-October) in the 5000m and 10,000m," Wanders said. 
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Julien Wanders clocks 13:29 in Monaco</div>
&nbsp;
&ldquo;For now I still want to improve on the track and see what I can do on the track and probably after Tokyo I will try my first marathon.&rsquo;&rsquo;
The versatile Hassan, who has put in world-class performances from 1500m to half-marathon, said she would take on the new challenge of contesting the IAAF World Cross Country Championships Aarhus 2019 in Denmark on 30 March.
&ldquo;I did European Cross Country a couple of times and I really like it so this year I&rsquo;m excited to do World Cross Country," she said.
In Doha, she also intends to contest the 5000m-10,000m double.
The 5km road distance was introduced as a <a href="https://www.iaaf.org/news/iaaf-news/competition-rule-amendments-june-2018">world record event in November 2017</a>, with the inaugural record to be recognised after 1 January 2018 if the performances were equal to or better than 13:10 for men and 14:45 for women. If no such performances were achieved in 2018, the best performances of 2018 would be recognised on 1 January 2019.
The pending inaugural records - 13:30 by Bernard Kibet on the men's side and 14:48 by Caroline Kipkurui in the women's for a mixed race - were set en route at the Birell Prague Grand Prix 10km on 8 September last year.
The morning also witnessed the tail end of an impressive two-day world record double. Less than 18 hours after helping pace Samuel Tefera to a world indoor record in the 1500m in Birmingham, Bram Som returned to action in Monaco, pacing Wanders through the first three kilometres of his world record run here.
Nicole Jeffery for the IAAF
* pending the usual ratification procedures

Julien Wanders of Switzerland and Sifan Hassan from The Netherlands raced to world record* performances at the inaugural 5km Herculis in Monaco on Sunday (17). 

Wanders and Hassan set world 5km records in Monaco

Julien Wanders broke his own European 10km record at the Corrida P&eacute;destre Internationale de Houilles while Gete Alemayehu smashed the course record as the 47th edition of the IAAF Silver Label road race was held in perfect conditions on Sunday (30).
Wanders, who had been ill earlier this month, said before the race that he felt he could finish within 28 minutes if he could regain some freshness. He exceeded his expectations, though, as he took seven seconds off the European record he set in Durban in October to win in a course of 27:25.
From the gun, the Swiss runner set out at an aggressive pace and covered the first kilometre in 2:41, four seconds inside European record pace. He led a group of six runners that included Ethiopian duo Berehanu Tsegu and Haftu Teklu, Uganda&rsquo;s Albert Chemutai and Kenya&rsquo;s Cornelius Kangogo, winner of the event in 2013, 2015 and 2016.
Tsegu took the lead from Wanders as the pack reached three kilometres in 8:12. The pace faded slightly leading up to the halfway point, which was reached in 13:47, but Wanders then decided to ramp up the tempo and the field broke up behind him. Only Tsegu was able to stick with Wanders&rsquo; relentless rhythm.
At about seven kilometres, with the bell ringing to signal it was the last of the race&rsquo;s three laps, Wanders was running at 27:30 pace. The 22-year-old managed to press on with two kilometres remaining and forged ahead of Tsegu.
Wanders, continuing his impressive display of strength, sprinted hard in the closing stages to retain his title in 27:25, 37 seconds faster than his winning time last year and 22 seconds faster than the previous course record of 27:47 set by Imane Merga in 2010.
&ldquo;My goal was to run at full gas,&rdquo; said a delighted Wanders. &ldquo;I didn&rsquo;t use a watch because it slows down the rhythm.&rdquo;
Tsegu finished runner-up in 27:36, 16 seconds ahead of Chemutai, both setting PBs.
Jimmy Gressier, the two-time European U23 cross-country champion, was the first Frenchman, finishing seventh in a French U23 record of 28:13. 
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Gete Alemayehu wins the Corrida P&eacute;destre Internationale de Houilles</div>
&nbsp;
While the men&rsquo;s race was a clear-cut affair, the women&rsquo;s contest was a close duel that went down to the wire.
Ethiopia&rsquo;s Gete Alemayehu proved to be the strongest at the end as she just got the edge of compatriot Helen Tola. The 20-year-old won in 31:12 to take 55 seconds off her previous PB.
Tola, who clocked a marathon best of 2:22:48 in Berlin in September, finished just one second behind, three seconds better than her previous PB.
Susan Jeptoo rounded the podium in 32:34. Cl&eacute;mence Calvin, who reduced the French record to 31:20 earlier this year, finished ninth in a more modest 34:00.
Quentin Guillon for the IAAF
<h3>Leading results</h3>
Men 1 Julien Wanders (SUI) 27:25 2 Berehanu Tsegu (ETH) 27:36 3 Albert Chemutai (UGA) 27:52 4 Filmon Ande (ERI) 27:57 5 Haftu Teklu (ETH) 28:09
Women 1 Gete Alemayehu (ETH) 31:12 2 Helen Tola (ETH) 31:13 3 Susan Jeptoo (KEN) 32:34 4 Karolina Nadolska (POL) 32:44 5 Oph&eacute;lie Claude-Boxberger (FRA) 32:50

Julien Wanders broke his own European 10km record at the Corrida Pédestre Internationale de Houilles while Gete Alemayehu smashed the course record as the 47th edition of the IAAF Silver Label road race was held in perfect conditions on Sunday (30).

Wanders breaks European record at Houilles 10km

Julien Wanders and Stacy Ndiwa claimed the titles at the Corrida Pedestre Internationale de Houilles, as the 46th edition of the IAAF Silver Label road race was held in windy and rainy conditions on Sunday (31).
Wanders&rsquo; victory in this 10km event put an end to 30 years of African dominance in Houilles. He&rsquo;s the first European runner to prevail in this race in the northwestern suburbs of Paris since Frenchman Paul Arpin&rsquo;s victory in 1987.
&ldquo;I want to win the race, and the time will follow,&rdquo; Wanders said before the race.
As usual, he set an aggressive pace from the outset and took command of the race with Ethiopia&rsquo;s Jemal Yimer by his side.
The first kilometre was hit in 2:44, suggesting a possible finish time of about 27:30.
Despite a headwind, Wanders continued to press on and the field broke up behind him. He reached two kilometres in 5:32, about 15 metres ahead of Yimer who shot out of the chasing group. At the end of the first of three 3.33km laps, Wanders led with a gap of about three seconds over Yimer, who was fifth in the 10,000m at the IAAF World Championships London 2017 where he set his PB of 26:56:11.
Yimer himself was about 15 metres ahead of the chasing group composed of four runners, including 2014 European steeplechase champion Yoann Kowal, Kenya&rsquo;s Cornelius Kangogo, a three-time winner at this event, Ethiopia&rsquo;s Yasin Haji and Florian Carvalho of France.
Wanders then slowed slightly, allowing Yimer to rejoin him between kilometres four and five. The duo passed the halfway point in 14:02, with the second group, spearheaded by Kowal, eight seconds adrift.
Wanders and Yimer reached the sixth kilometre in 16:50 as the chase pack splintered. Hayato, who didn&rsquo;t manage to bridge the gap behind the leaders, carved out a lead over Kowal, Kangogo and Carvalho, who began to falter. It became obvious Yimer and Wanders would battle for the victory.
The Swiss runner made his first move 7.5 kilometres into the race. Although Yimer began to struggle with the pace, he managed to stick with him. One kilometre later and as the rain came down, Wanders made his decisive attack and was ultimately rewarded for his efforts. Yimer, who was the fastest entrant of the field courtesy of a 27:54 PB set in September, drifted back but didn&rsquo;t give up.
Wanders managed to hold off the Ethiopian&rsquo;s late comeback in the closing stages to break the tape in 28:02, 15 seconds outside the 27:47 course record set by Ethiopia&rsquo;s Imane Merga in 2010. The 21-year-old also improved his own Swiss record by 11 seconds.
&ldquo;I took my responsibilities,&rdquo; Wanders said. &ldquo;When Yimer came back, I decided to adapt my tactic. I slowed down a bit to save some energy for the final. I gave everything in the last kilometre. I didn&rsquo;t give up and I&rsquo;m very happy because it paid off.&rdquo; Wanders said his next races will be half marathons, including the IAAF World Half Marathon Championships in March.
Hayato finished third in 28:27, while defending champion Kangogo finished fourth in 28:53, one second ahead of Kowal.
<h3>Ndiwa leads Kenyan sweep in women&rsquo;s race</h3>
Stacey Ndiwa of Kenya fulfilled her role of favourite in the women&rsquo;s race. She led the race from start to finish to win in 31:35, placing 35th overall. Her compatriot Evaline Chirchi, whose only outing this season was a 48:54 performance over 15km in Nijmegen, wasn&rsquo;t able to sustain the pace and eventually drifted to second.
Fifth at the 2015 World Cross Country Championships, Ndiwa confirmed her current form as she improved her PB this autumn in two back-to-back races, clocking 31:37 in Prague and then 31:27 in Ziwa.
Chirchir was second in 32:10 as Magdalene Masai, who ran a 31:44 PB in April, rounded out the podium, one minute behind the winner.
Quentin Guillon for the IAAF
<h3>Leading results</h3>
Men 1 Julien Wanders (SUI) 28:02 2 Jemal Yimer (ETH) 28:03 3 Yasin Haji Hayato (ETH) 28:27 4 Cornelius Kangogo (KEN) 28:53 5 Yoann Kowal (FRA) 28:54
Women 1 Stacey Ndiwa (KEN) 31:35 2 Evaline Chirchir (KEN) 32:10 3 Magdalene Masai (KEN) 32:36 4 Rosie Clarke (GBR) 33:03 5 Mekdes Woldu (ERI) 33:27

Julien Wanders and Stacey Ndiwa claimed the titles at the Corrida Pedestre Internationale de Houilles, an IAAF Silver Label road race whose 46th edition took place in windy and rainy conditions on Sunday (31).

Fab five: world records set in 2019

Advice to my younger self: Julien Wanders

World records ratified

Wanders and Hassan set world 5km records in Monaco

Wanders breaks European record at Houilles 10km

Wanders and Ndiwa triumph at Houilles 10km