Heat Is On Coleman And World Championships Organisers

Controversial US sprinter Christian Coleman's bid for 100 metres gold took centre stage at the World Championships on Saturday as endurance athletes prepared for another battle with Doha's punishing heat and humidity.

Coleman romped to a 9.88sec win in his semi-final to underline his intention to clinch his first major championship outdoor title, just weeks after escaping a lengthy anti-doping ban because of a technicality.

Coleman has received strong public backing from world athletics chief Sebastian Coe, who has defended the American's right to be regarded as a clean athlete.

The 23-year-old from Tennessee narrowly avoided a ban after failing to properly notify drug testers of his whereabouts on three occasions in a 12-month period -- an offence normally punishable by a one-year suspension.

"We have to be very careful not to play fast and loose with the reputation of athletes," Coe said on Friday following criticism of Coleman by US sprinting legend Michael Johnson.

"I am pleased Coleman is here and I want to make sure he is given every opportunity to be one of the faces of these Championships," the IAAF president added.

Coleman has angrily denied any suggestion he is guilty of taking performance-enhancing drugs.

Defending champion Justin Gatlin kept his hopes alive of a third world 100m title but only just, scraping through into the showdown later in the day as one of the two fastest losers.

While Coleman is seeking his first world outdoor title, Jamaican legend Shelly-Ann Fraser-Pryce got off to a terrific start in her bid to win a fourth 100m world gold.

The 32-year-old two-time Olympic champion timed an impressive 10.80sec, the fastest women's 100m heat in world championship history.

Renaud Lavillenie's desperate search for an elusive world gold to add to his 2012 Olympic pole vault title will have to wait another two years as the 33-year-old Frenchman failed to qualify for the final.

'It's a catastrophe'

Coe and other IAAF organisers meanwhile will be nervously keeping an eye on Saturday's two endurance walking finals, the men's and women's 50-kilometre races.

The races get under way at 11:30pm local time in what are expected to be sweltering conditions.

The walks take place 24 hours after the first day's women's marathon in which Kenya's Ruth Chepngetich took gold after an arduous test of endurance that saw 28 of 68 starters fail to finish.

The IAAF announced the show would go on, stating no one had suffered heat stroke in the marathon and the completion rate was comparable to women's races at Tokyo in 1991 and Moscow in 2013.

However, the distressing spectacle of the marathon -- some competitors were stretchered off and another placed in a wheelchair -- made a deep impression on France's decathlon world champion Kevin Mayer.

"Clearly by organising the championship here, they (the IAAF) didn't put the athletes first, they've mostly put them in jeopardy," said Mayer, who is also the world record holder.

"Even if people aren't saying it out loud, it's obvious it's a catastrophe."

The marathon havoc will have done nothing to calm the angst of France's 50km walk champion Yohann Diniz, who defends his title on Saturday.

Diniz angrily hit out at organisers on Friday for forcing walkers to race in the heat while track and field athletes are competing in a comfortable 25 degrees Celsius in the climate-controlled Khalifa Stadium.

"I am disgusted by the conditions," the Frenchman said.

"I am extremely upset. If we were in the stadium we would have normal conditions, between 24-25 degrees, but outside they have placed us in a furnace, which is just not possible."

Aside from the 100m and the two walks, three other titles will be decided -- the men's long jump, the women's hammer and the women's 10,000m.

The latter event should ensure a sizeable contingent of Ethiopian and Kenyan spectators, who proved invaluable in livening up the atmosphere on the opening day.