It will take Shahrul Izwan roughly 35 seconds to complete the T52/53 100m wheelchair race when he makes his Asean Para Games (APG) debut on Wednesday, but the 23-year-old's journey to the starting line has taken considerably longer than that.

Before he lost the use of his legs to a condition known as spastic paralysis, he rode a mountain bicycle and represented East View Secondary School in floorball.

But in 2009, when he was 15, the Secondary 3 student noticed something was wrong.

He recalled: "I could feel that my legs were getting weaker and weaker.

"I thought then that maybe it was because I was training and running around too much. So I just needed to stop training and join a more relaxed CCA (co-curricular activity)."

He switched to dikir barat, a Malay form of performing arts, but walking became more difficult and the next moment of alarm came two years later.

"I was walking along a straight pavement with my dad. There were no rocks and it wasn't a rough surface, but I just tripped and (my legs gave way)," said Shahrul, the eldest of four siblings.

At the hospital, an initial X-ray did not provide any clues, but he said an MRI scan revealed a growth "inside my brain", affecting his spinal cord and his mobility.

He was told that surgery was a risky option and so he decided against it, although he found it hard to come to terms with his deteriorating condition.

As his ability to walk was steadily eroded, he went from using crutches in 2011 to needing a wheelchair in 2014.

"Because of this condition, I lost a lot of confidence in myself," the 23-year-old said.

"I wanted to give up on life, because I used to be active but this thing stopped me from doing what I wanted in life."

Instead of going out with his friends, he stayed mostly at home and played computer games if he had no classes at the Institute of Technical Education College East.

Now a third-year electrical and electronic engineering student at Temasek Polytechnic, he said candidly: "It is hard to concentrate or to follow what the lecturer says."

Shahrul, who sometimes has to pause before replying, explained: "I have to take a longer time to think and it's slower than before."

Last year, his sister urged him to take up a sport again and helped searched online for suitable activities for him to participate in.

He was grateful for her advice, saying: "My sister didn't want me to see me inactive, whereas in the past I went out often with my friends."

In October, he joined the national para-athletics team for a training session at the Kallang Practice Track and tried wheelchair racing for the first time.

It was hard initially as he struggled to propel himself .

"I was skinny and thin because I had lost weight and was not active," he said.

"Wheelchair racing was not as easy as I had expected. Even in a 100m race, it was tough to keep within a lane and go straight. And (it took) a lot of strength."

What he lacked in energy he made up for in determination, said his coach Jaffa Mohamed Salleh, who also trains Rio Paralympian wheelchair racer Norsilawati Sa'at.

Jaffa added: "He has grown so much, be it in self-confidence, focus during training, determination and physique. He used to not have a lot of confidence in himself, his physique was too skinny, he looked clumsy and I was unsure about his commitment."

In May, Shahrul competed at the World Para Athletics Grand Prix in Beijing and, as the only participant in the T34 class, clocked 34.68sec in his first international meet.

The Kuala Lumpur APG offers him much more than just the chance to compete in the international arena again.

There is a far deeper personal significance.

"I've grown more confident in myself," he admitted.