Kalai Vanen stands at 1.82m tall with a muscular upper body. Even without his left leg, his military background lends an imposing air to the 56-year-old.

While he can easily bench-press over 150kg, he is anything but a mean machine, with his frequent smiles and loud guffaws.

Yet, his friendly demeanour masks a stirring comeback story after losing his left leg when he was just 29.

At 22, he was diagnosed with Giant Cell Tumour of the Bone, a disease which saw a 34-inch (86.3cm) tumour grow around his left leg.

He then spent seven years trying to find alternative cures, to no avail.

He recalled: "I clung on to hope, but the tumour grew too big and the best thing was to amputate it."

With that decision, his career in the army ended, and he remained unemployed for over 10 years.

While he got married at 29, the burden of raising a family weighed him down.

"I had my tumour, I wasn't moving on in life, and my then-girlfriend, now wife, had her own family concerns about her getting married and that led to me being suicidal," he said.

"I contemplated suicide many times. Many, many times."

Ultimately, it was also his family that pulled him through that dark period.

"It was the fact that they're around me that pulled me together. How could I leave my wife and kids to fend for themselves? That motivated me to move on," he said.

Vanen finally found his groove when he landed his dream job as a personal trainer in a gym.

He recalled: "I started going back to the gym, a couple saw me and asked me to help them with getting fit. So that was how it started - by accident."

Coincidentally, it was also by accident that he picked up powerlifting when his old friend and fellow para athlete Raja Singh, encouraged Vanen to try the sport.

However, unlike powerlifting for the able-bodied which has three components - the bench press, squat and deadlift - powerlifting for the disabled has only one component which is the bench press.

Depending on their disabilities, athletes may not have the luxury of having both feet on the ground.

"I had to re-learn things in terms of stability and balance," said Vanen. "Also, I have to improvise things like my standing, lying or sitting position.

"I do not have a lower body to balance myself so I can tip over anytime while carrying the weight."

Yet, that has not stopped Vanen from training up to four times a week to prepare for the APG.

In just eight months, he has managed to carry 155kg, a 55kg increment from when he started out.

Said his coach Muhammad Hidayat: "It's beyond expectation for a novice."

Yet for Vanen, the very fact that he is able to represent Singapore at the APG is a source of immense pride and satisfaction.

"I feel that there is a huge responsibility on me to do well," he said. "I would very much like to win a medal, regardless of the colour."

And through the many challenges he has faced, he learnt one important thing: "The circumstances or situation doesn't define me, it is how I deal with it that defines me.

"So I never give up because my life is limitless. It is up to me to decide how I live."