To understand the external demons faced by shot putter Valerie Adams at her fourth Olympics, look at the London Games podium.

In the centre stands Belarusian Nadzeya Ostapchuk, the cheating 'champion' who would soon be exposed for using the banned substance metenolone. Her four-year ban ends on August 14, two days after the Rio competition.

To her left is Evgeniia Kolodko. Last month, retrospective tests revealed she submitted a positive doping sample at the same meet.

Adams has always been burdened by this toxic environment as she charts a course to become New Zealand's first gold medal winner at three consecutive Olympics.


Among Kiwis, only Adams, middle distance runner Sir Peter Snell, rowers Dick Joyce, Caroline and Georgina Evers-Swindell, coxswain Simon Dickie, kayakers Ian Ferguson and Paul MacDonald and equestrian rider Sir Mark Todd have won gold at successive Games.

The disqualification of Adams' London rivals has hardened her view that Rio must proceed without Russian participation.

"It is the only way to nip it in the bud," Adams told the Herald on Sunday from her Swiss base. "People say, 'what about the clean Russian athletes?' My response is, 'what about us, the clean athletes worldwide?'

"This Russian regime is bigger than them as individuals. I feel heartbroken for the fourth and fifth place-getters [who would have received medals at London]. Their moment is gone."

Adams knows all about 'gone' moments. At Athens, her maiden Games, she missed the top eight and the opportunity for three more puts. Four of those ahead of her have since received doping bans.

"To save our sport and prevent younger athletes from doing such stupid things, they needed to take a stance. That's a good thing."

Adams says such cases indicate a systemic problem which goes beyond federations or sporting bodies.

"Good on the IOC [International Olympic Committee], Wada [World Anti-Doping Agency] and the IAAF [track and field's world governing body]. If you wring the chicken by the neck, the chicks underneath will not do that."

Adams' frustration is understandable. She is the only woman to win four consecutive shot put world championships, yet her best performances rank with the also-rans.

The 31-year-old is one of two female shot putters who have won back-to-back Olympic titles. The other was Soviet Tamara Press in 1960 and 1964. Yet Adams, with access to the wonders of modern sports science, remains 23rd on the all-time distance list.

Her 21.24m best was set at the 2011 world championships in South Korea. The world record of 22.63m, set by Soviet Natalya Lisovskaya at Moscow in June 1987, remains 1.39m beyond her reach.

Back in the real world, Adams' march towards Rio gold still looks promising.

New Zealand boasts famed examples of athletes fighting back into the Olympic gold reckoning. They include the Evers-Swindell twins' 0.01s rowing victory over Germany in the 2008 double sculls, Yvette Williams' last-gasp long jump qualification of 1952 and Todd's clear showjumping round in 1984 before American Karen Stives dropped the 13th fence of 15 to present him the eventing title.

Adams threw a season's best 19.69m to win the Rome Diamond League a month ago.

She's yet to heave beyond 20m since returning from surgery last year but her main rivals - German Christina Schwanitz, American Michelle Carter and China's Lijiao Gong - are within her arc.

Gong (20.43m in May) and Carter (20.21m to win the world indoor championships in March) are the only puts beyond 20m in competition this season.

World champion Schwanitz last month recorded 19.49m as she recovers from a shoulder injury.

"It is an even playing field and probably one of the tightest for Olympic year," Adams says. "The level is not as high as previous Games, which is exciting because I'm breathing down their necks. That's good for my confidence, especially knowing I'm in good physical shape."

Schwanitz is the key athlete to monitor. She set a personal best 20.77m in May last year. Adams has not bettered that mark in competition since beating Schwanitz with 20.88m at the 2013 world championships. Schwanitz has blossomed, cracking 20m nine times in 2015, including the top four heaves.

The scenario boosts anticipation for the Olympics, something Adams relishes after a recent training discovery which could translate to extended distance.

"It was a bad habit I picked up to take pressure off after my knee problems. I spotted it on a video and was astonished. Coming off the back of the circle, I'm meant to push from my heel but I was coming on to my toe and pushing off.

"Mechanically, it didn't add up. That's minor for those who don't know much about shot put, but has had a big impact. I'm back throwing with better heel placement."

Adams competes at the Monaco Diamond League on July 15 and has a meet in Budapest three days later before bunkering down for Rio.

Hopefully she gets a clean shot at the title.