More than 1500 athletes from 145 teams are set to compete at the&nbsp;World Athletics U20 Championships Cali 22&nbsp;between 1-6 August.
Here we take a look at the men&rsquo;s and women&rsquo;s race walks and combined events&nbsp;at the Pascual Guerrero Olympic Stadium. 
<h2>Women&rsquo;s 10,000m race walk</h2>
Just weeks after Japan&rsquo;s success in the race walks at the World Athletics Championships Oregon22, the nation heads to Cali with hopes of another 1-2 finish, this time in the women&rsquo;s 10,000m race walk.
Ai Ooyama and Ayane Yanai are the fastest entrants for the championships, thanks to their road clockings of 45:19 and 45:21 respectively. Ooyama, who will be one of the youngest athletes in Cali, will be making her track debut, but if she is able to match her speed from the roads, then it should put her in medal contention.
Australia&rsquo;s Olivia Sandery already has considerably experience across a range of distances and surfaces. She holds the fastest time on the track this year by an U20 athlete with her 45:24.1 PB from January. A fifth-place finish at the World Race Walking Team Championships in March has no doubt fired up Sandery ahead of the World U20 Championships.
Ukraine&rsquo;s Valeriya Sholomitska also won&rsquo;t be short of motivation. The 17-year-old finished fourth at the World U20 Championships last year and at the World Race Walking Team Championships earlier this year. Since fleeing her home country earlier this year, she has been training and racing in different locations around the world.
Heta Veikkola finished strongly at the World Race Walking Team Championships to finish third. She went on to set PBs for 5000m (22:11.54), 5km (22:44) and 10km (46:02), which suggests her track 10,000m PB of 49:39.40 is due for serious revision.
Italy, another strong race walking nation, will be represented by Giada Traina, who has a best this year of 46:51.44. She didn&rsquo;t finish at the World Race Walking Team Championships but may fare slightly better on the track and in the kinder conditions of Cali. 
<h2>Men&rsquo;s 10,000m race walk</h2>
Heristone Wanyonyi, surprise winner of this title in Nairobi last year, will defend his title but this time the Kenyan takes on a much tougher line-up than before.
The 19-year-old may not have the fastest times to his name, but that&rsquo;s mainly because most of his races have either been at altitude or in extreme temperatures. He clocked 42:10.84 to win the title last year and is about a minute shy of that so far this year, but he was competitive at the World Race Walking Team Championships in Muscat, placing fourth. And the three men who finished ahead of him there won&rsquo;t be in Cali.
Turkey&rsquo;s Mazlum Demir, who led for several kilometres at the World Race Walking Team Championships before fading and eventually finishing 11th, heads to Cali as the fastest man in the field. He clocked a national U20 record of 40:42.09 in June and he&rsquo;ll be keen to improve upon his sixth-place finish from last year&rsquo;s World U20 Championships.
Unsurprisingly, Japan and Italy have fielded strong teams in the race walks. Shotaro Shimoike and Riku Ooie will compete for Japan, both of whom have come close to breaking 41 minutes on the roads, while Italy will be represented by Nicola Lomuscio and Emiliano Brigante, whose track PBs are among the quickest in the field.
Colombia&rsquo;s Mateo Romero finished just two seconds behind Wanyonyi in Muscat earlier this year. The home crowd advantage could spur the 19-year-old to an even higher finish in Cali.
Algeria&rsquo;s Ismail Benhammouda, Ecuador&rsquo;s Terry Patricio Villacorte and Guatemala&rsquo;s Bryan Matias could all contest for medals too. 
<h2>Heptathlon</h2>
Saga Vanninen could become the first two-time world U20 heptathlon since Carolina Kluft achieved the feat 20 years ago.
The talented Finn was one of a handful of athletes last year to win gold at the World U20 Championships and European U20 Championships. She won the latter with a PB of 6271, a national U20 record.
She came close to that mark with 6193 in Oulu in late June, her second score in excess of 6000 points this year. She&rsquo;ll likely need a similar performance in Cali if she is to keep the strong German contingent at bay.
Sandrina Sprengel won the German U20 trials with a PB of 6015, but the competition was relatively close with Serina Riedel taking second place with 5894. Apart from the shot put, where Vanninen excels, these leading three entrants are relatively closely matched in most disciplines, so the competition should be a gripping one.
Estonia&rsquo;s Liisa-Maria Lusti should also be in medal contention. She has a PB of 5836 and will likely bank some big points in the jumping events. She is entered for the individual long jump and is a reserve for the high jump, an event in which she has a 1.86m PB. 
<h2>Decathlon</h2>
Jacob Thelander heads to Cali with a score that&rsquo;s 200 points better than any other decathlon entrant, but the Swedish all-rounder can&rsquo;t rest on his laurels as there are five other athletes with PBs in excess of 7500.
Thelander finished seventh at the European U20 Championships last year but has built on that experience and improved to 7823 this year, helped by strong performances in the jumps. Expect him to bank some big points in the high jump in particular, especially if he can match his 2.10m PB from earlier this year.
If, however, that event doesn&rsquo;t go to plan for him, the likes of Spain&rsquo;s Pol Ferrer, Yoram Vriezen of the Netherlands or French duo Pierre Blaecke and Sacha Rifflart could capitalise.
Ferrer recently improved by more than 400 points to win the Spanish U20 title with 7623. And while he set some big PBs within that series, he was some way off his best in the 400m, the javelin and the 1500m, which suggests there&rsquo;s potentially even more to come from him.
Vriezen, Blaecke and Rifflart have all improved significantly this year and will be keen to ride that wave through the battle for medals.
Norway&rsquo;s Abraham Sandvin Vogelsang is also worth keeping an eye on. While his season&rsquo;s best is 7385, he scored 7535 at the European U20 Championships last year and finished ahead of Thelander.
Others with medal potential include Germany&rsquo;s Roman Jocher, Czech Republic&rsquo;s Petr Svoboda and Gabriel Emmanuel of the Netherlands.
Jon Mulkeen for World Athletics

World Athletics U20 Championships

A look at the men's and women's combined events and race walks.

WU20 Cali 22 preview: combined events and race walks

An Australian wave was expected to swamp these Oceania Championships. It still may, but Rellie Kaputin showed that it will not swamp everything in its path.
The 26-year-old from Papua New Guinea provided the shock of day one and &ndash; a further prediction: make of it what you will &ndash; is likely to stand up as the shock of the championships when she defeated Australians Brooke Stratton and Naa Anang to take the gold medal in the women&rsquo;s long jump.
The huge upset came after Jemima Montag and Rhydian Cowley had banked two gold medals for Australia in the race walks.
The 10,000m track events were also part of the IAAF Race Walking Challenge and, like all events at these area championships, came with the bonus of additional area championship points under the IAAF ranking system to be used for qualification for the Tokyo 2020 Olympic Games.
Additionally, the warm and humid conditions in Townsville were something of a test run for the conditions athletes can expect both at the IAAF World Athletics Championships Doha 2019 later this year and in Tokyo.
Both Commonwealth 20km champion Montag and Cowley, Olympic and World Championships representative, are coached by Brent Vallance, who guided the career of Jared Tallent through to the gold medal in the 2012 Olympic 50km.
Montag, 21, faced strong opposition from even-younger teammate Katie Hayward, fifth in the 10,000m at last year&rsquo;s World U20 Championships in Tampere and second to Montag&rsquo;s third in Adelaide earlier this year.
The pair matched strides early before Montag upped the pressure.
&ldquo;The focus was on getting points and winning the race,&rdquo; Montag said. &ldquo;Then, if I got to 15 laps (6km) feeling good, push on.&rdquo;
At the finish, Montag&rsquo;s personal best 43:50.84 saw her almost two minutes clear of Hayward with Claire Woods well back in third.
Montag said Vallance had told her the Oceania race was a good learning opportunity.
&ldquo;With Naples (World University Games) and Doha, we thought maybe this is a good development opportunity, a chance to get one up on those who may not get a hot-weather race in the lead-up,&rdquo; said Montag.
Cowley also used a strong second half to break away from world U20 fourth-place finisher Declan Tingay. His 41:57.57 put him 45 seconds ahead at the line.
Cowley said he was well-prepared. &ldquo;Jemima and I have both been doing sessions in a heat tent.&rdquo;
Cowley said he was also benefitting from moving into full-time work. &ldquo;The routine of going to work and training after work seems to be paying dividends,&rdquo; he said.
<h3>Last jump does it for Kaputin</h3>
Kaputin waited for the last jump to clinch her surprise win. Her 6.50m effort pushed her a mere centimetre clear of Stratton&rsquo;s 6.49m, and a hand-span ahead of Anang&rsquo;s 6.44m.
With two other jumps measuring 6.41m, it was the third time in the competition Kaputin had exceeded her previous national record of 6.39m (she also has a marginally wind-aided 6.53m to her credit from 2017).
None of these distances seemed likely to trouble the Australians coming into the championships. The pair faced up several times through the not-long-concluded domestic season and were regularly jumping distances in the 6.70-range. But neither could find a winning jump when it mattered. Stratton&rsquo;s next best in the competition was 6.47m. For her part, Anang had a second-best of 6.40m, again well down on previous form. 
<div id="5d121a4cdbb88713b85f3c82" class="dropMedia">
<div style="background-image: url('https://media.aws.iaaf.org/media/Small/5864b9c9-4cd6-44d0-82d5-ef7518e0c12f.jpg');">&nbsp;</div>
Rellie Kaputin of Papua New Guinea in action in the long jump</div>
&nbsp;
Kaputin will be chasing a second gold medal in the triple jump later in the championships.
A more expected shut-out of the hosts came in the women&rsquo;s shot put where New Zealand pair Maddison-Lee Wesche and Victoria Owers took first and second place with Tonga&rsquo;s Atamaata Tu&rsquo;utafaiva taking the bronze. Wesche, the world U20 champion, was beyond 18 metres with her best put of 18.04m.
<h3>Another 1-2 for New Zealand in the 5000m</h3>
New Zealand took another gold and silver brace in the men&rsquo;s 5000m, Oli Chignall prevailing over Matthew Baxter, 14:07.17 to 14:08.87, in a close finish to a slow race. Australia&rsquo;s Andrew Buchanan was a distant third.
The warm daylight conditions were not ideal for endurance events, but Australia took a medal sweep in the women&rsquo;s 5000m through Melissa Duncan, Paige Campbell and Tara Palm. Duncan and Campbell, Australia&rsquo;s top two finishers at the World Cross Country Championships in Aarhus, ran 15:41.44 and 15:46.25 respectively, with Palm recording 16:35.16.
<h3>Lowis making successful transition to senior ranks</h3>
World U20 javelin champion Nash Lowis is showing little apparent difficulty in making the transition to the senior ranks.
The 19-year-old has already thrown beyond 80 metres with the senior implement. He did not need that distance here, but his 79.10m was close and almost two metres to the good of Australian teammate Liam O&rsquo;Brien&rsquo;s best of 77.32m. O&rsquo;Brien has also gone past 80 metres this year, but he could not find that sort of form here.
Australia had another win in the men&rsquo;s pole vault, which was taken out by Angus Armstrong at 5.40m, from teammate Steven Clough and New Zealand&rsquo;s Nick Southgate.
<h3>Decathletes Moloney and Dubler chasing World Championship qualifiers</h3>
World U20 champion Ashley Moloney and Cedric Dubler are both on track for a score in excess of 8000 points after the first day of the decathlon.
The pair both competed in G&ouml;tzis five weeks ago. On that occasion, Moloney was second overall on the first day with 4436, but ultimately it was Dubler who finished ahead of his younger Australian teammate, 8185 to 8038.
Dubler was just 41 points shy of his G&ouml;tzis first-day score here with 4210 after the first five events. He opened with a 10.85 in the 100m, long-jumped 7.32m, threw the shot 12.09m and then, in his best first-day event, cleared 2.13m in the high jump. He closed with a 48.43 in the 400m.
Moloney tallied 4293 through the first five events. He had an edge in the 100m, where he ran 10.59, the long jump &ndash; 7.52m, and the shot put &ndash; 13.48m. But a sub-par high jump &ndash; just 1.92m &ndash; left him needing something special in the 400m to close the day on a good note. He produced it, too, a 46.75 to slice 0.11 off his personal best, set in his gold medal competition at the World U20 Championships last year.
With Dubler having the stronger second day, the decathlon could come down to the last event. The question is whether either athlete can push past the 8200 World Championships qualifier.
Len Johnson for the IAAF

An Australian wave was expected to swamp these Oceania Championships. It still may, but Rellie Kaputin showed that it will not swamp everything in its path.

Australian race walkers strike gold while Kaputin surprises in long jump at Oceanian Championships

Six thousandths of a second &ndash; in any event, it&rsquo;s a minuscule sliver of time, a winning margin that could easily leave the defeated athlete feeling hard done by.
In an event as long and arduous as the 10,000m race walk, that feeling is only likely to be exacerbated, but at the IAAF World U20 Championships Tampere 2018 there were no hard-luck stories for Ecuador&rsquo;s David Hurtado.
For 40 minutes, the 19-year-old had walked his heart out, covering the 25 laps of the track both carefully and courageously, so when his final charge up the home straight fell short by the tiniest of margins, he had no regrets.
&ldquo;My main target was winning the gold but throughout the race it became very difficult because I got two yellow cards,&rdquo; said Hurtado. &ldquo;So I decided to take it easy up until 8km and then just try as much as I could at the end.&rdquo; 
<div id="5b49c313160340078446d33d" class="dropMedia">
<div style="background-image: url('https://media.aws.iaaf.org/media/Small/388d00c7-a0d1-4eb8-a2dc-86478e2b2117.jpg');">&nbsp;</div>
Zhang Yao and David Hurtado in the 10,000m race walk at the IAAF World U20 Championships Tampere 2018</div>
&nbsp;
Turning into the home straight, Hurtado had a six-metre deficit to make up on China&rsquo;s Zhang Yao, but with a surging finish he flashed past the finish in unison with Zhang, both athletes clocking 40:32.06, both athletes walking away exhausted, drenched in sweat from their exertions under an oppressively warm midday sun.
For Hurtado, reaching that line and earning silver for Ecuador was the culmination of a journey started 10 years earlier, when his interest in the sport was first stoked by watching a hero of his on TV.
<h3>Inspired by Perez</h3>
Hurtado was just nine years old during the 2008 Beijing Olympics but he, like most Ecuadorians, closely followed the exploits of Jefferson Perez, who, despite then reaching the autumn of his career, took a superb silver medal in the 20km race walk.
&ldquo;Obviously he inspired me,&rdquo; said Hurtado. &ldquo;I remember watching him in 2008 and that&rsquo;s when I understood what competitive race walking was and I wanted to do the same. I&rsquo;m very, very proud to represent race walking now for Ecuador.&rdquo;
It&rsquo;s hard to overstate the esteem with which Perez is held in Ecuador. An Olympic gold medallist at the 1996 Olympics, upon returning home from Atlanta Perez embarked on a 459km pilgrimage in his native country, giving thanks for his success with an 11-day trek between Quito and his hometown of Cuenca.&nbsp;
That golden celebration drew huge crowds to the roadside each day, cementing his status as a national hero. In the decade that followed, that status only grew as Perez added three world 20km titles and an Olympic silver medal in Beijing.
Only three years after those 2008 Games did Hurtado first take up the sport, encouraged to try it by one of his teachers at school. His performances improved rapidly and a year later, at the age of 13, Hurtado was passed to a specialist race walking coach in Javier Callambe.
These days, he continues to train under the guidance of Callambe, who has him covering about 70 kilometres a week in training.
&ldquo;At the moment we&rsquo;re doing a very meticulous job and the aim is to improve it step by step and in the future to get better,&rdquo; said Hurtado.
Hurtado trains in Quito, the Ecuadorian capital, where he attends university and studies sports marketing, and though there is no race walking background in his family, his proud parents were following his exploits from afar when Hurtado flew the Ecuadorian flag in Tampere.
<h3>Silver lining</h3>
Heading into the IAAF World U20 Championships, all eyes were on Zhang, the Chinese star who won the world U18 title last year and had backed it up with the U20 10km title at the IAAF World Race Walking Team Championships in Taicang earlier this year.
With warm sun beating down from above on the morning of the men&rsquo;s 10,000m race walk, halfway was reached in a conservative 20:43.39, with Hurtado and Zhang nestled in the pack which was led by Kenya&rsquo;s Dominic Samson Ndigiti.
Hurtado made his move shortly after, clocking a 3:52.19 split between 6000m and 7000m to whittle the leading pack. However, by then Hurtado had picked up two yellow cards and was at risk of an unwanted 60-second penalty trip to the pit lane. 
<div id="5b572104e239a212741160b4" class="dropMedia">
<div style="background-image: url('https://media.aws.iaaf.org/media/Small/59a8d6b0-9150-475b-9ebe-ecdf080f74e2.jpg');">&nbsp;</div>
David Hurtado of Ecuador in the 10,000m race walk at the IAAF World U20 Championships Tampere 2018</div>
&nbsp;
As a result, he had to hold back and play a cat-and-mouse game with Zhang over the final three laps, Zhang making his decisive move at the bell and opening up an advantage that he would hold until the dying metres, when Hurtado made his last-gasp drive for gold.
It didn&rsquo;t come off, but silver did not only exceed many people&rsquo;s expectations; it also surpassed the bronze medal won by Hurtado&rsquo;s hero Perez at this event back in 1990.
Given what Perez went on to do after that performance, Hurtado now sees no reason not to dream of similar success as he transitions to the senior ranks.
&ldquo;My biggest dream is to win an Olympic medal,&rdquo; he says.
Cathal Dennehy for the IAAF

Six thousandths of a second – in any event, it’s a minuscule sliver of time, a winning margin that could easily leave the defeated athlete feeling hard done by. 

Silver in Tampere felt like – and nearly was – gold for Hurtado

After covering 25 laps of the track in uncomfortably warm conditions, just six thousandths of a second separated the top two finishers at the end of the men&rsquo;s 10,000m race walk at the IAAF World U20 Championships Tampere 2018.
Zhang Yao was bidding to become the first man in history to complete a full set of global age-group race walking titles. The Chinese teenager had already won two out of a possible three, having triumphed at the IAAF World U18 Championships Nairobi 2017 and in the U20 10km event at the IAAF World Race Walking Team Championships Taicang 2018.
And for 9,980 metres of today&rsquo;s 10,000m race walk, he looked well on his way to pick up a third global title. Ecuador&rsquo;s David Hurtado, though, produced an inspired effort down the final home straight and crossed the line level with Zhang.
A nervous wait followed. Zhang had punched the air with delight as he crossed the line, but the longer it took for the results to become official, the more unsure he became about whether he had taken the gold medal.
After a couple of minutes, it was finally confirmed: Zhang had won the title in 40:32.06. Hurtado was given the same time in second place, but just six thousandths of a second separated them in the photo finish: 40:32.054 to 40:32.060.
The race got underway at a steady pace. Japan&rsquo;s Sho Sakazaki led during the early stages, taking the field through 1000 metres in 4:03.30 and 2000 metres in 8:17.33.
Kenya&rsquo;s world U18 bronze medallist Dominic Samson Ndigiti then led for several laps with Sakazaki, Japanese compatriot Tatsuhiko Nagayama, Poland&rsquo;s Lukasz Niedzialek and David Kuster of France all near the front.
Australia&rsquo;s Kyle Swan made a brief appearance at the head of the pack, while his teammate Declan Tingay was a few strides back in the middle of the leading group. By 4000 metres, reached in 16:35.20, Zhang and Chinese teammate Wang Zhaozhao were right behind Ndigiti, so too were Guatemala&rsquo;s Jose Ortiz, Australian duo Swan and Tingay, plus Hurtado.
Little had changed in the positions of the leaders at half way, which Ndigiti passed in 20:43.39. Hurtado made his move soon after, though, and the pace gradually started to pick up.
A 3:52.19 split between 6000 and 7000 metres blew the field apart, leaving just Hurtado, Zhang and Ortiz out in front. Ortiz stuck with the leading pair for another 1000 metres before he started to struggle, but he was relatively safe in third place.
Hurtado and Zhang, meanwhile, continued to play a cat-and-mouse game during the closing stages. Zhang hit the front with three laps left, but the Ecuadorian went back into the lead with 700 metres left.
As the bell sounded for the final lap, Zhang went back into the lead and opened up a four-metre lead on Hurtado. Possibly thinking his lead was bigger than it actually was, Zhang appeared to ease off slightly on the final home straight. Hurtado picked up his cadence and started to close in on the Chinese leader.
The race reached its exciting conclusion with the pair crossing the line in unison before Zhang was later declared the winner.
&ldquo;I&rsquo;m quite surprised I won,&rdquo; said Zhang. &ldquo;I have worked hard for this for seven years. This title means a lot to me.&rdquo;
Although slightly disappointed to miss out on the gold medal, Hurtado was proud of his achievement.
&ldquo;My goal was to win the gold medal but it became difficult for me as I got two yellow cards, so I took it easy up to 8km and then tried as much as I could,&rdquo; he said. &ldquo;It was very hot and I felt dehydrated during the race.&rdquo;
With Ortiz holding on to take bronze with 40:45.06, all three medallists were rewarded with PBs. Tingay was fourth in 40:49.72, breaking the Oceanian U20 record that had previously been held by Olympic bronze medallist Dane Bird-Smith.
Jon Mulkeen for the IAAF

After covering 25 laps of the track in uncomfortably warm conditions, just six thousandths of a second separated the top two finishers at the end of the men’s 10,000m race walk at the IAAF World U20 Championships Tampere 2018.

Report: men’s 10,000m race walk – IAAF World U20 Championships Tampere 2018

The order from the U20 10km at the IAAF World Race Walking Team Championships in Taicang, China in May was repeated on the track as the 10,000m race walk reached a thrilling three-way climax on the fifth morning of competition at the IAAF World U20 Championships Tampere 2018.
Mexico's Alegna Gonzalez stayed away from the lead until the final 600 metres but the 19-year-old timed her effort brilliantly, pulling away from Ecuador's Glenda Morejon and Turkey's Meryem Bekmez to win her second major title of the season in a world U20 leading time of 44:13.88.
On a warm morning in Tampere, Puerto Rico's Rachelle de Orbeta staked out her claim from the gun and led by 11 seconds by the two kilometre checkpoint in 8:54.19. The pack which included all of the medal favourites --and the three eventual medallists-- were content to bide their time and de Orbeta was swallowed up by the pursuers just after the three kilometre mark.
After the halfway point was reached in 22:41.39, Bekmez was the first of the principal contenders to make a show, making an early bid for the title with 11 laps to go. The world U18 silver medallist over 5000m led by four seconds at the seven kilometre mark courtesy of a quick kilometre of 4:13.75 but Gonzalez and Morejon moved up as a pair and were back in title contention after eight kilometres.
Perhaps remembering how quickly Gonzalez finished to beat her in Taicang two months ago, Morejon began to press --but not hard enough-- with five laps remaining as Bekmez and Gonzalez sat comfortably in her slipstream. With one-and-a-half laps remaining, the Mexican moved to the front for the very first time which put paid to Morejon's title chances. Bekmez resisted for longer but a gap began to open up to Gonzalez with 300 metres remaining. Maintaining her technique all the way to the line, Gonzalez --who didn't receive any warnings from the judges-- was rewarded with her second major age-group accolade of the summer, also with a North American U20 record of 44:13.88.
"I'm happy with how the race went. It's been a really good season, exactly what I hoped for. This was a strategical competition and I had a lot of fuel in the tank in the end of the race," said Gonzalez, also expressing a penchant for the warm conditions. "This was perfect weather for me."
The silver and bronze medal positions remained in flux for the last 300 metres but Bekmez spurted again with 120 metres, opening up a comfortable gap on a tiring Morejon, 44:17.69 to 44:19.40. Bekmez set a Turkish U20 record while Morejon was rewarded with a South American U20 record on her 10,000m track debut.
"I only turned 18 in May so I think I have a long path ahead of me. Next my coach wants me to compete in Peru to improve my marks for the Tokyo Olympics in 2020," she said.
Seventeen of the top 20 finishers all set lifetime bests including early leader de Orbeta, seventh in a national U20 record of 45:51.58.
Steven Mills for the IAAF

The order from the U20 10km at the IAAF World Race Walking Team Championships in Taicang, China in May was repeated on the track as the 10,000m race walk reached a thrilling three-way climax on the fifth morning of competition at the IAAF World U20 Championships Tampere 2018.

Report: women’s 10,000m race walk – IAAF World U20 Championships Tampere 2018

Zhang Yao will aim to become the first man in history to complete a full set of global age-group race walking titles.
The Chinese teenager has already won two out of a possible three, having triumphed at the IAAF World U18 Championships Nairobi 2017 and in the U20 10km event at the IAAF World Race Walking Team Championships Taicang 2018.
He will naturally start as the favourite in Tampere where conditions may be far kinder than in his two previous global championship appearances. He set a 10,000m PB of 41:12.01 in the altitude of Nairobi and recorded a 10km best of 40:07 in the heat and humidity of Taicang. He may need to go faster than he ever has done before to secure a third major title.
As he found out in Taicang earlier this year, he won&rsquo;t have an easy ride. Teammate Wang Zhaozhao could prove to be his toughest opponent and he has been getting closer to Zhang in each of their recent races, finishing just five seconds adrift to take the silver medal in Taicang.
Japan finished a close second to China on the medals table in Taicang and they can once again be expected to provide stiff opposition in Tampere. Sho Sakazaki finished fifth in Taicang, but he&rsquo;ll start the 10,000m race walk in Tampere as the athlete with the fastest PB (39:52.45) and season&rsquo;s best (40:17.82) on the track.
Compatriot Tatsuhito Nagayama missed out on selection for Taicang, but that same weekend clocked a 10,000m PB of 40:55.14 in Tokyo and will be keen to impress on his major championships debut.
Guatemala&rsquo;s Jose Ortiz Flores finished fifth in Nairobi and third in Taicang and will be keen to maintain that upward trajectory.
Australia&rsquo;s Declan Tingay picked up three red cards in Taicang so was forced to wait in the pitlane for one minute before resuming, but he went on to place 14th.
Kenya&rsquo;s Dominic Ndigiti and Ethiopia&rsquo;s Yohanis Algaw represent a new wave of African race walkers and pose a very real threat. Ndigiti took bronze at last year&rsquo;s World U18 Championships, while Algaw finished sixth in Taicang with an African U20 record of 40:56.
The European challenge, meanwhile, comprises the likes of 2016 European U18 champion Lukasz Niedzialek, French U20 record-holder David Kuster and Belarusian Mikita Kaliada.
Jon Mulkeen for the IAAF

Zhang Yao will aim to become the first man in history to complete a full set of global age-group race walking titles.

Preview: men’s 10,000m race walk – IAAF World U20 Championships Tampere 2018

Mexico&rsquo;s Alegna Gonzalez and Ecuador&rsquo;s Glenda Morejon finished first and second over 10km at the IAAF World Race Walking Team Championships in Taicang in May and they will resume their rivalry over the same distance but this time on the track in Tampere.
Gonzalez covered the 10km distance in 45:08 to defeat Morejon, the world U18 5000m race walk champion, by five seconds on an oppressively humid day. The good news is the conditions should be decidedly fresher in Tampere but the bad news for her rivals is Gonzalez is almost one minute faster than the rest of the field on paper with a 44:43.89 PB set at the Pan-American U20 Championships last summer.
Third in the U20 race in Taicang, Japan&rsquo;s Nanako Fujii will arrive with aspirations of claiming her second major medal of the season. Even though China isn&rsquo;t sending their very best exponents to Tampere, Shi Yuxia and Liu Yajing are still ranked inside the top 10 albeit on the roads with 45:02 and 45:18 respectively.
Turkey might not have quite the lustrous tradition in race walking as some of the aforementioned nations but Meryem Bekmez has been a regular on the podium in recent championships.
In the space of six days last year, the 17-year-old earned a silver medal at altitude over 5000m at the World U18 Championships in Nairobi and then a bronze medal on a sweltering morning in Grosseto over 10,000m at the European U20 Championships.
Steven Mills for the IAAF

Mexico’s Alegna Gonzalez and Ecuador’s Glenda Morejon finished first and second over 10km at the IAAF World Race Walking Team Championships in Taicang in May and they will resume their rivalry over the same distance but this time on the track in Tampere.

Preview: women’s 10,000m race walk – IAAF World U20 Championships Tampere 2018

As the 2012 Olympic 50km race walking champion and multiple winning World Championships medallist, Jared Tallent may today be a superstar in his art but back at the 2002 World Junior Championships his status was quite different. Here the Australian reflects on his underwhelming experience in Kingston, Jamaica and, crucially, what he learned from his Caribbean adventure.
<h3>Background</h3>
To pick Jared Tallent out as a potential future Olympic champion at the 2002 IAAF World U20 Championships would have taking a big leap of faith.
After all the whippet-thin Australian finished a distant 19th out of 25 finishers in the men&rsquo;s 10,000m race walk four minutes and more than two laps down on the gold medallist that day in Kingston&rsquo;s National Stadium.
It was a disappointing display for the teenager who grew up on a potato farm near Ballarat, Victoria, but one which helped forge the resolve to train hard and one day scale the race walking heights on the global stage.
Introduced to race walking in his early teens, Tallent quickly established a natural flair for the discipline. In 2001 he made his international championship debut competing at the IAAF World Youth Championships in Debrecen and he has many fond memories of the event.&nbsp;
&ldquo;I had a great time there,&rdquo; he recalls. &ldquo;We had an Olympian on the Australian team in Georgie Clarke (aged 16 she competed in the 1500m at the 2000 Sydney Olympics) and I remember she seemed like a superstar to me. I made a lot of friends from the competition and it was exciting to compete against kids the same age from all around the world.&nbsp;
On the track, Tallent performed with pride finishing seventh in the men&rsquo;s 10,000m race walk and took many positives out of the experience leading into the World U20 Championships in Kingston 12 months later.
Enjoying a natural improvement in early 2002 he posted a 10,000m race walk lifetime best of 43:36:03 in Canberra &ndash; in a race he fondly recalls as it was his first competing against his countryman Nathan Deakes, who would go on to win 2004 Olympic 20km bronze and 50km gold at the 2007 World Championships.
<h3>Competition memories</h3>
Yet his preparation received a jolt after the Australian team gathered in the Bahamas for the pre-event training camp.
&ldquo;I found it a hard place to train,&rdquo; he says. &ldquo;It was not a great location for a walker. I didn&rsquo;t always want to train at the track and I found the roads were really busy and the footpaths quite uneven. I ended up doing a lot of work on the treadmill, although training in an air- conditioned gym didn&rsquo;t really help me get used to the climate.&rdquo;
Additionally, the Australian team were housed next to the casino which proved an unwelcome distraction.
&ldquo;The hotel probably wasn&rsquo;t in the best location,&rdquo; explains Tallent. &ldquo;In the Bahamas, you only need to be aged 16 to go to the casino and I lost 100 bucks playing roulette &ndash; I don&rsquo;t think I&rsquo;ve ever told my parents.&rdquo;
Enduring a far from ideal preparation on the day of his 10,000m race walk he then suffered further stress after hearing that the plane carrying his parents from Australia had been delayed. As his parents only intended to fly into Jamaica on race day, this led to unnecessary agitation for the then 17-year-old.
&nbsp;
<div id="5730a7888ef8ed0e580917d6" class="dropMedia">
<div style="background-image: url('https://media.aws.iaaf.org/media/Small/e179c9ab-4c3f-431d-b690-556341ebfb41.jpg');">&nbsp;</div>
Jared Tallent in action at the IAAF World Race Walking Team Championships Rome 2016</div>
&nbsp;
&ldquo;I remember getting stressed out that I had not seen my parents and that they may not make the race,&rdquo; he recalls. &ldquo;The first time I saw them was taking their seats on the back straight as I was being led out to the track.&rdquo;
Given pre-race advice from his coach to take up a good position in the race the inexperienced Tallent then took this a little literally be quickly tucking into second place and going through the 1km marker in the lead.
&ldquo;I really shouldn&rsquo;t have been worried about my position so early as it is a 25-lap race,&rdquo; he recalls.
By halfway the Australian had dropped off the lead pack and then in the second half of the race with his pace dropping and his brittle confidence waning he found the experience tough.
&ldquo;I was lapped twice by the gold medallist, but I think I approached the race in awe of many of these athletes who were two minutes quicker than me (in terms of PBs). I was thinking negatively, that I couldn&rsquo;t get near these guys.
Crossing the finish line in 45:41:19 in 19th was not what he desired and he finished the race in a despondent mood.&nbsp;
&ldquo;I was disappointed with my performance after spending all that time away from home,&rdquo; he says. &ldquo;It was a good experience, but not the result I wanted.&rdquo;
On the plus side, he recalls the thrill of watching a 15-year-old Usain Bolt strike 200m gold in the front of his passionate home supporters and he fondly reflects the home fans &ldquo;climbing the walls&rdquo; to squeeze into the National Stadium for the final day of action.
<h3>Lessons Learned</h3>
The result may not have gone how Tallent wanted but the knowledge he accrued from the experience should not be undervalued.
&ldquo;I came home very motivated to train hard and prepare for my next championship,&rdquo; he recalls. &ldquo;I&rsquo;d seen what other athletes were doing in terms of their training and this made me think of ways I could improve.
&ldquo;It also taught be the value of being in a good training environment before a championship. In recent years, for example, I have not attended the pre-World Championship training camp for Australia because it has not suited the needs of a race walker. I have found a different location &ndash; which is something I learned from being in the Bahamas.&rdquo;
Next month in Finland the latest edition of the IAAF World U20 Championships takes place in Tampere, in which the planet&rsquo;s finest teenage talent will once again come together for six days of exhilarating competition.&nbsp;
For Tallent the action will be intense and exciting, but the 33-year-old passes on some wise words to all those competing athletes.
&ldquo;The World U20s are a stepping stone for bigger and better things in the future, so I would say to the athletes (in Tampere) to enjoy it and don&rsquo;t get too hung up on your finishing position. It is much more of a learning experience.&rdquo;
Steve Landells for the IAAF

As the 2012 Olympic 50km race walking champion and multiple winning World Championships medallist, Jared Tallent may today be a superstar in his art but back at the 2002 World Junior Championships his status was quite different. Here the Australian reflects on his underwhelming experience in Kingston, Jamaica and, crucially, what he learned from his Caribbean adventure.

Teen trials to senior success – Jared Tallent

The boys&rsquo; 10,000m race walk was a historic race for several reasons.
Not only did Zhang Yao win China&rsquo;s first world U18 title in this discipline, but Dominic Ndigiti earned Kenya&rsquo;s first global championships medal in a race walking event.
At the beginning, Sanjay Kumar seemed intent on making a similar piece of history for India and shot to the front, covering the first lap in 1:24 and the first 1000 metres in 3:44.76, well inside world U18 best pace. He was closely followed by Ndigiti and the pair had already built up a lead of 100 metres within the first kilometre.
Thankfully the pace soon started to settle and they covered the second kilometre in a more sensible 4:05. The chase pack, led by Ethiopia&rsquo;s Meseret Ayelign, was still 22 seconds adrift, but they were operating at a more even tempo.
The pace slipped further in the third kilometre as Kumar and Ndigiti covered that section in 4:13. Salavat Ilkaev and Sergey Kozhevnikov, competing as neutral athletes, and Yao made up ground on the lead pair after a 4:07 kilometre.
Sixteen minutes into the race, Kumar was called into the pit lane for two minutes after being shown three red cards for loss of contact. It meant that Ndigiti was left alone out in front and, having passed 4000m in 16:22.77, his lead was down to eight seconds.
Within the space of two laps, Yao had closed the gap on Ndigiti and moved on to the Kenyan&rsquo;s shoulder with Ilkaev close behind. At half way, passed in 20:35.58, a lead pack of five athletes had formed as Kozhevnikov and Guatemala&rsquo;s Jose Ortiz joined Ndigiti, Yao and Ilkaev.
The quintet strode together for three more kilometres before Yao darted to the front. He was followed by Ilkaev but had a comfortable lead and continued to pull away from his opponents.
Yao was away and clear, while Ilkaev was safe in the silver medal position, but with two laps to go, Kozhevnikov moved alongside Ndigiti in the battle for bronze.
Yao crossed the line in a world U18 leading 41:12.01 with Ilkaev taking silver in 41:24.17. Cheered on by an enthusiastic home crowd, Ndigiti doggedly held on to his position and made up a lot of ground on Ilkaev, eventually finishing third in 41:25.78. Kozhevnikov finished fourth in 41:26.65.
&ldquo;The race went as planned,&rdquo; said Zhang. &ldquo;My strategy was to follow in the first two kilometres of the race and then lead in the last two kilometres, which worked.&rdquo;
Ndigiti, meanwhile, was delighted with his performance. &ldquo;I used a lot of energy since I lacked a teammate to pace for me,&rdquo; he said. &ldquo;That made me slow down on my last lap because I couldn't sprint anymore. However, I am happy to deliver Kenya a medal in such an event.&rdquo;
Jon Mulkeen for the IAAF

The boys’ 10,000m race walk was a historic race for several reasons.

Report: boys' 10,000m race walk – IAAF World U18 Championships Nairobi 2017

Guatemala has never won a medal at an IAAF championships, but Jose Eduardo Ortiz could end that spell in Nairobi.
Although he has relatively limited racing experience, Ortiz is the fastest U18 athlete in the world this year in the 10km race walk. He clocked a best of 40:58 on the roads to finish a close second in the U20 race at the Pan American Race Walking Cup in May.
But with this year&rsquo;s World U18 Championships being held at altitude, the race may not go entirely to the formbook because difficult conditions can often lead to surprise results.
China will be represented by Zhang Yao, winner of the U20 race at the Mario Albisetti Memorial in Lugano, and Qian Haifeng, both of whom have recorded season&rsquo;s bests well inside 42 minutes. They will aim to win China&rsquo;s first gold medal in a boys&rsquo; race walking event at the IAAF World U18 Championships.
Meanwhile, Mikita Kaliada of Belarus and Lukasz Niedzialek of Poland will renew their rivalry. At last year&rsquo;s European Youth Championships, Niedzialek built up a big lead in the boys&rsquo; 10,000m race walk before Kaliada essentially ran to gain the lead in the closing stages, only to be disqualified for loss of contact and leaving Niedzialek to rightfully claim the gold medal.
Kaliada gained some redemption at the European Cup in Podebrady in May, finishing one place and nine seconds ahead of Niedzialek to take the silver medal in a PB of 41:19, and he&rsquo;ll be keen to do so again in Nairobi.
Salavat Ilkayev, competing as a neutral athlete, could also challenge for a medal.
Jon Mulkeen for the IAAF

Guatemala has never won a medal at an IAAF championships, but Jose Eduardo Ortiz could end that spell in Nairobi.

Preview: boys' 10,000m race walk – IAAF World U18 Championships Nairobi 2017

There&rsquo;s only so much waiting anyone can take. For 10,000m race walk winner Callum Wilkinson, his limit is about 15 minutes.
That&rsquo;s roughly how long the Briton waited in the middle of the lead pack before sweeping to the front and cranking up the pace with each lap.
The opening tempo was slow, with Turkey&rsquo;s Salih Korkmaz taking the field through 1000m in 4:17.16 and 2000m in 8:40.38. Half a lap later, Germany&rsquo;s Leo Kopp decided to take up the pace and he led through 3000m in 12:54.57.
The pace had increased, but it still wasn&rsquo;t fast enough for Wilkinson&rsquo;s liking.
Within the space of one lap, Wilkinson had taken pole position and stretched out the lead pack. Korkmaz was still near the front, so too was Noel Ali Chama of Mexico. But from 4000m onwards, reached in 17:02.91, Wilkinson did not relinquish his lead.
After another 4:08 kilometre to reach half way in 21:11.75, Wilkinson moved up another gear and began to churn out sub-four-minute splits for the remaining 1000m sections.
A 3:58.47 kilometre saw the lead pack reduce to nine. Manuel Bermudez, the silver medallist in the junior race at the IAAF World Race Walking Team Championships Rome 2016, began to drift behind the leaders as the Spaniard struggled with a minor ankle injury.
At 7000m, Ecuador&rsquo;s Jhonatan Amores and Ethiopia&rsquo;s Yohanis Algaw were still doggedly sticking to Wilkinson, but the Briton was showing no signs of stress. Wilkinson covered the penultimate 1000m section in 3:53.56 and just four men were left in contention.
As the pack went through the bell, Algaw was the first to drop off, leaving just Wilkinson, Amores and Korkmaz in the hunt for medals. But those positions remained the same throughout the last lap as Wilkinson stretched away to win in a national U20 record of 40:41.62, crossing the line in utter disbelief.
Not only was it the fastest time in the world this year by an U20 athlete, it also takes Wilkinson to second on the senior British all-time list for the distance.
&ldquo;Every lap of the track made me more and more confident,&rdquo; said Wilkinson after covering the second half in 19:29.87 and the final kilometre in 3:44.51. &ldquo;I can&rsquo;t believe I did it. I knew I could, but I can&rsquo;t believe it. I&rsquo;m just in shock. It&rsquo;s everything I wanted this year. This is it.&rdquo;
His gold medal is Britain&rsquo;s first race walking title in a major international age-group competition. The last Briton to win a global race walking title was 1964 Olympic 20km champion Ken Matthews.
Amores finished second in a PB of 40:43.33, taking Ecuador&rsquo;s first world U20 medal in this discipline since Jefferson Perez won gold in 1992. Korkmaz crossed the line in 40:45.53, while Algaw was fourth in an African U20 record of 40:55.96.
Jon Mulkeen for the IAAF

There’s only so much waiting anyone can take. For 10,000m race walk winner Callum Wilkinson, his limit is about 15 minutes.

Report: men's 10,000m race walk – IAAF World U20 Championships Bydgoszcz 2016

China&rsquo;s Ma Zhenxia is just 17 years old, but already she owns four major global titles.
Winner of the Youth Olympic title in 2014, the world U18 title in 2015 and the junior title at the IAAF World Race Walking Team Championships Rome 2016, Ma added another gold medal to her collection by winning the women&rsquo;s 10,000m race walk at the IAAF World U20 Championships Bydgoszcz 2016.
Ma was always present in the lead pack. She took the field through the first 1000m in 4:39.27 before settling into a pack which also included Finland&rsquo;s Taika Nummi, Ethiopia&rsquo;s Yehualeye Beletew, Italy&rsquo;s Noemi Stella and Japan&rsquo;s Yukiho Mizoguchi.
Nummi upped the pace for the second kilometre, which was covered in 4:27.57, which led to Beletew picking up a couple of red cards before reaching the 3000m checkpoint.
Less than two seconds separated the top 12 women at 3000m, reached in 13:44.01, and the group increased in numbers as the pace dropped in the fourth kilometre.
Nummi, Belatew, Stella and Ma continued to share the lead for a few more laps, gradually increasing the pace. By 7000m, with Beletew leading the group through that checkpoint in 32:07.16, just six women were left in the lead pack with Mexico&rsquo;s Valerie Ortuno and China&rsquo;s Jiang Shanshan joining Beletew, Nummi, Ma and Stella.
Stella, Ma and Beletew then broke away and were three seconds ahead of the rest of the field at 8000m. It was clear that, barring a disaster, the medals would go to those three women.
With three laps to go, Ma and Stella began to forge ahead. Knowing that she already had two red cards to her name, Beletew played it safe and didn&rsquo;t attempt to challenge the leaders.
Ma moved into the lead with two laps to go but Stella was still right behind. Ma still had another gear to move into for the last lap and she stretched away to win by six seconds in a world-U20-leading 45:18.45, having covered the final 1000m in 4:15. She became the first Chinese winner of this title since Liu Hong in 2006.
Stella crossed the line in a season&rsquo;s best of 45:23.85, while Beletew took bronze with an African U20 record of 45:33.69. Ortuno was further behind in fourth, but also set a continental U20 record, crossing the line in 45:44.33.
Having finished fourth in Rome earlier this year, Noemi was delighted to make it on to the podium in Bydgoszcz.
&ldquo;This is the biggest success of my career,&rdquo; said the 2013 world U18 bronze medallist. &ldquo;I did not expect this, but during the race I felt good and I just did the best I could.&rdquo;
Just twelve months after compatriot Ayalnesh Dejene earned bronze at the IAAF World Youth Championships Cali 2015, Beletew doubled Ethiopia&rsquo;s tally of global race walking medals.
Jon Mulkeen for the IAAF

China’s Ma Zhenxia is just 17 years old, but already she owns four major global titles.