Thornton turns to 200m for added speed

Sometimes it's best to do big things by halves.

It's why teenage sprint star Jessica Thornton plans to focus on the 200m to speed up her specialty race, the 400m.

Thornton was Australia's youngest track and field athlete at her debut Olympics, where she made it to the final of the women's 4x400m relay.

The 18-year-old had very nearly earned herself an individual berth, bettering the 400m qualifying mark at last month's world under-20 championships but missing the cut-off by several days.

Thornton came fourth in the final in Poland with a personal-best 52.05 seconds, beaten to a medal by two thousandths of a second.

In the first leg of her team's relay heat in Rio, she burst out of the blocks and ran 51.79.

Thornton hopes to shave more off, ideally at next year's world championships in London and the 2018 Commonwealth Games on the Gold Coast.

The key, she believes, could be concentrating on the half-lap event.

"I have to speak to my coach but we might be planning to come back next year and do the 200m, focus on that," Thornton said.

"To be able to run a 50-second 400m I need to be running 22.50 seconds or lower even (in the 200).

"So I need to get the speed up for the 200 before I can go even faster for the 400."

Australia's relay team of Thornton, Morgan Mitchell, Anneliese Rubie and Caitlin Sargent-Jones came eighth in the final.

Incredibly, the young and inexperienced quartet would have trumped Great Britain for the bronze medal had they reproduced their heat time of 3:25.71 seconds, which was nearly two seconds faster.

The girls were the first team to represent Australia in the event since Melinda Gainsford-Taylor, Tamsyn Lewis, Nova Peris and Cathy Freeman finished fifth in Sydney 2000.

And the new generation, still deciding whether to nickname themselves the Sugar Gliders or the Sheilas, are now chasing their predecessors' national record of 3:23.81.

"We ran 3:30 at the Glasgow Commonwealth Games - that's five seconds in two years," said Rubie.

"I can't say we'll run another five seconds quicker in two years' time, but we can definitely go faster and faster."