She had no professional coach or proper training routine.

Yet Madam Mary Klass stood out as one of Singapore's pioneer female athletes in the then largely male-dominated arena of competitive sport.

"Back in the 50s, women had to train very hard to get into serious sports," she said. "Monday to Friday, I would go to the public fields or tracks near my home to train at 5.30am and at 5pm. Without fail."

Now 83, the grandmother of four will face the crowds again - this time in a short film to be screened during the National Day Parade at The Float @ Marina Bay. Her journey as one of Singapore's first female Olympians will be among the five real-life stories in the film that showcase the Singaporean spirit.

"I was shocked when they first told me that I was picked for NDP... It is a great honour. I never expected that my story would inspire people," said Madam Klass.

The sprinter retired in 1957, after winning a silver medal in the 1954 Asian Games in Manila and being among the first women to represent Singapore at the 1956 Melbourne Olympics.

This was despite reservations from her father who initially thought she was "wasting time". "I ran not just to win. I ran to prove to others that I could succeed and to better myself, and better my timing." said Madam Klass.

With no guidance from professional coaches, she started training at 17 with former athletes and other sprinters at stadiums and fields.

Madam Klass said she was honoured to have been able to "stand tall" for Singapore. "To Singaporean youth, be proud of what you want to do and what you want to achieve, train hard and always stand tall for your country."