Two years ago, rock-climbing coach Chua Chee Beng fell from a height of 7m in an accident and suffered multiple fractures, including in his ankle and spine.
Doctors told him that he could be paralysed in his right leg because the fall had damaged nerves to his spine.
But within two months, the now 50-year-old was back on his feet walking with crutches, and he hit the rock-climbing wall again in four months.
In November, he will be embarking on a 50km charity walk called Let's Take A Walk, organised by non-profit group Raleigh Singapore, which is a registered society of volunteers dedicated to paying it forward through adventure.
Mr Chua, who is an operations manager at Active Global Fitness, which runs fitness programmes, credits his wife, friends at Raleigh, where he volunteered on occasion from 1994, and the physiotherapist, for his recovery.
Back in Aug 8, 2017, he was helping a friend to set up climbing ropes for a photo shoot at a wall in Dairy Farm Road when he fell.
"I was careless and overconfident," he told The Sunday Times on Friday. But those who know him know that he is usually obsessed with not making mistakes, he added.
The accident was in part caused by miscommunication between him and his friend, who was supposed to check whether the rope had reached the ground.
Mr Chua, who has more than 20 years' experience in rock climbing, said: "But I don't blame him as I could have taken more safety measures, such as tying a knot at the end of the rope to break the fall."
During his recovery, he feared that he would no longer be able to coach effectively.
He also had to deal with the uncertainty of not knowing when he would be able to climb again.
"Sometimes when I see that my trainees are doing the drills wrongly, and I explain to them, they cannot understand. When I want to demonstrate but cannot, it's very demoralising and frustrating."
After his accident, Mr Chua stopped teaching competitive sports. He had previously taught sports climbing and track and field at the former Tampines Junior College, Canberra Primary School, and Bedok View Primary School.
"(But) I had a lot of injuries before the fall, and I never believed that any injury would set me back and not allow me to do what I want again," said Mr Chua, who was an army regular for 19 years before leaving in 2009.
Active in sports since young, he signed on during his Basic Military Training and eventually became a physical training instructor who conducted, planned and supervised fitness training in the army.
Four months after his accident, even before he could walk without crutches, he started climbing again, after working with his physiotherapist and doing simple stretches and exercises daily.
On Dec 25 that year, as his Christmas present, he made his first climb since the fall.
He scaled an 8m-tall wall at the side of his landed property in West Coast, with his wife as the belayer, or the person on the ground who secures the climber.
His wife, 48, is a manager of a car workshop. They have three children aged 14, 12 and 10.
Mr Chua, who now walks with a slight limp, has so far covered up to 20km at one go in preparation for the 50km challenge, which he will take on with the aid of walking sticks. "For injuries, you will recover from them if you are hungry enough. You may not get back 100 per cent, but how many per cent you get back is how much you try."