One of Canada's best remaining hopes for a medal at the world track and field championships in London is entered in a race she has little hope of winning.

Melissa Bishop is the Canadian and Pan American Games champion at 800 metres and is the reigning world championship silver medallist. The 29-year-old from Eganville, Ont., finished a dramatically close fourth at the Olympics in Rio last summer, despite lowering her national record to 1:57:02.

Bishop has since shaved the record again, by a hundredth of a second, while finishing fifth in a Diamond League race in Monaco last month.

She has extended her career in order to prove to herself that what she has done so far hasn't merely been an exercise in futility.

"I can't let a rule ruin my enjoyment of the sport," Bishop said over the phone from her training base in Windsor, Ont., prior to leaving for London and the world championships. "I really want to be on the podium. It may not be first or second but I believe I can get there."

Thinking about her fourth-place finish in the women's 800 metres at the Rio Olympics still brings Canadian runner Melissa Bishop to tears. "It's like a pain in your side that won't go away," she says. 3:41

The "rule" Bishop is referring to is a 2015 Court of Arbitration for Sport decision that overturned an IAAF regulation requiring female athletes with naturally elevated testosterone levels to supress those levels in order to compete. The most notable example of such an athlete is two-time Olympic 800-metre champion Caster Semenya of South Africa — the intersex runner who has been subject of much controversy since she won her first of two world titles in 2009.

Semenya demonstrates qualities of hyperandrogenism, has significantly higher levels of testosterone when compared to most of her rivals and has proven to be virtually unbeatable at 800 metres. The IAAF is challenging the CAS ruling with evidence from a new study published by the British Journal of Medicine that quantifies the advantage hyperandrogenic female athletes have.

But the ruling, which allows these athletes to compete without testosterone-inhibiting drugs, will stay in place for these world championships, and any changes will not come in time for Bishop to enjoy a more level playing field in her event.

"It's about setting my own goals," Bishop reckoned. "It's got to be worth it for me. For me to be able to continue, I have to love it."

Bishop knows that, no matter how fast she runs, she's unlikely to escape the shadow of the powerful Caster Semenya. (Frank Gunn/Canadian Press)

Against all odds

Bishop's dilemma is one that athletes consistently face in track and field. Confronted with scenarios which offer them little chance of tangible reward, they choose a path that resists the temptation to quit or complain, instead opting to stay in the race with the hope of a more personal victory. The same is true of many marathoners who hail from anywhere but Sub-Saharan Africa.

"Melissa is the strongest person I know," said Canadian women's marathon record holder Lanni Marchant. "We all want to be the best in class, but we also are chasing being our best and have to accept whatever result or outcome that is. For some of us it will never be a medal. But that is the beauty of running."

Members of the Canadian technical team in London, who are supporting Bishop and other athletes who consistently race against odds which are beyond their control, point to the fact that sport promises no foregone conclusions.

"I absolutely do believe there are many intangible factors that dictate the outcome of events," said Dr. Trent Stellingwerff, the head physiologist for Athletics Canada in London. He says that statistical analysis cannot account for things like ability to handle pressure, negotiate race tactics or the complete "unpredictable chaos" of traffic in a race like the 800 metres.

"So I'm very happy to report that, sure, some athletes might have better incoming odds than others, but we will all have to tune in and sit on the edge of our seats and watch the drama unfold."

A podium spot could be in reach, but Bishop knows she may have to be satisfied with a personal best at the worlds in London. (Cameron Spencer/Getty Images)

'Anything is still possible'

Penny Werthner, the Dean of Kinesiology at the University of Calgary, leads the mental performance team in London and is essentially Athletics Canada's head psychologist. A medallist at both the Pan American and Commonwealth Games, Werthner ran the 1500m at the 1976 Olympics in Montreal and believes athletes like Bishop cannot afford to believe the outcome of any race is pre-determined.

"It is an environment where much is possible and much is unpredictable, and for every Usain Bolt we have many who will win once or twice only. It is why we watch," she reasoned.

"The focus must be on oneself and how smooth, fast, powerful, alert and smart I can be. That is what allows the physical body to do what it has trained to do. This perspective is what will allow for one's best performance, for a personal best. It is what an athlete wants to ask for. And when they get it right, great things can happen."

Essentially, that is what Melissa Bishop is seeking. In order to have a chance at a medal, she'll need to run close to the perfect race. The beauty is, she believes that is achievable.

"I hate putting a limit on myself and I will never do that as long as I race," she stressed.

"Everybody's human. We are not robots. Caster Semenya is a human being. There's a lot of traffic, and things happen out there. I'd like to believe that anything is still possible."

In other words, for Bishop, there can be no excuses and no turning back now.

Her decision is made.

In spite of being an underdog and facing odds which may be stacked against her, she races on — determined to find an elusive, inner triumph.