DOHA, Qatar -- Oksana Chusovitina is proof that age is nothing but a number.

Almost three times as old as some of her competitors, the 43-year-old put herself in contention Saturday to make the vault final at the world gymnastics championships. Yes, you read that right. A 43-year-old is not only hanging with teenagers athletically but also continuing to show most of them how it’s done.

“I don't know where I find motivation from,” Chusovitina said. “But I love gymnastics so much, and that's why I continue doing it.”

It’s a fact of nature that people lose flexibility as they get older, which is why gymnastics – women’s gymnastics, in particular – has typically been a sport for the young. Oh, there have always been outliers, and Aly Raisman and Russia’s Aliya Mustafina have shown that you can continue to compete into your 20s if you take care of your body and are smart about your training.

But competing into your 30s, let alone 40s? That just isn’t done.

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Except by Chusovitina.

This is her 16th world championships. Her first worlds was in 1991, meaning she’s been at a world-class level since before all of her competitors were even born. (Seriously. Mustafina wasn’t born until 1994.) Chusovitina has competed long enough that she initially represented the Soviet Union, and was part of the Unified Team at her first Olympics, in 1992.

She now competes for Uzbekistan.

There’ve been times Chusovitina said her competitive days were coming to an end. That whatever world championships or Olympics she was at would be her last. But she now says she plans to go through the Tokyo Olympics in 2020.

“We are women, that's how we are,” Chusovitina said with a sly smile. “We are changing our moods all the time."

And, really, why should she retire? She’s healthy, she’s still competitive and, most importantly, she’s still enjoying it.

“I have fun,” she said.

Chusovitina knows people are fascinated by her longevity, but she doesn’t see it as anything special. She’s just doing what she loves, what she’s always done, and this is where it’s brought her.

As for how she relates to her (much) younger competitors – Uzbek teammate Sabina Turobova just turned 16 last month, making her almost two years younger than Chusovitina’s son, Alisher, who turns 19 next month -- Chusovitina said it’s really not that hard.

“When we compete, we all are equal on stage,” Chusovitina said. “Even though we have different age, we have to perform in the same way."

Except there's no one like Chusovitina. Not even close.

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Follow USA TODAY Sports columnist Nancy Armour on Twitter @nrarmour.