Associate engineer Hung Tee Keong does not exercise.
He cannot even remember the last time he stepped into a gym.
The closest he comes to weight training is during the once-a-month grocery shopping he does with his wife. He carries the grocery bags.
Yet, last Wednesday, Mr Hung, 47, and 29 others worked together and helped lift a container truck enough to free a man who had been pinned underneath after an accident.
Their rescue effort was captured on a video that went viral online, with the original video being shared almost 6,000 times.
"An empty container truck weighs between 5 tonnes (5,000kg) and 7.5 tonnes. Loaded, it can go up to 20,000kg," Dr Wang Qinghai, a senior lecturer with the Department of Physics at the National University of Singapore's Science Faculty, told The New Paper.
Dr Wang said if the truck was empty, each of the 30 rescuers would have lifted an average of 166kg each. (See report right.) "That would be almost double a man's weight," the physics lecturer added.
President of the Singapore Weightlifting Federation Tom Liaw said a man who is not trained to lift weights would not be able to lift 160kg and sustain it for two seconds.
A Filipino design engineer, who wanted to be known only as Dennis, said last Wednesday that the men lifted the truck high enough and long enough for him to go under it and pull the injured man out.
"I did it instinctively. I was afraid that those lifting the truck might get tired, so I made sure to keep as low as possible. An Indian man helped me.
"The two of us managed to pull him out. It happened very quickly," he told the media last Wednesday. How tough a challenge is it to lift that weight?
"A trained weightlifter, weighing between 90 and 100kg, could possibly lift 160kg longer.
"Without a situation where there is an adrenaline rush, they would not be able to lift the truck for over two seconds," Mr Liaw added. An adrenaline rush is a sudden burst of energy from an increase in the hormone, adrenaline.
It increases the heart rate and blood pressure, perspiration, blood sugar, and metabolism and spurs people to action. With adrenaline, the body's entire stress response contributes to superhuman strength.
In 1982, American mum Angela Cavallo lifted a 1,588kg car high enough to replace the jack when the car slipped off and fell on her teenage son, pinning him in the wheel well.
When The New Paper informed Mr Hung that he may have lifted a whopping 166kg that day, the associate engineer with automotive supplier Continental Automotive was surprised.
"I don't know how I managed to do that. When I was helping to lift the truck, my mind was focused only on helping the victim. I guess it was a case of mind over matter," said Mr Hung.
His colleague, IT senior executive Andrew Tung, 35, who also helped in the rescue effort, agreed.
The more active Mr Tung, who plays badminton three times a week and tries to go to the gym at least once a week, said: "I may be healthy, but I don't think I'm very strong. Still, 166kg is an amazing feat. I can't explain how we could have lifted that weight."
The New Paper understands that the victim, believed to be a 35-year-old South Korean surnamed Kim, is in a stable condition and has been transferred to a general ward.
Mr Kim's associate told The Straits Times that he has declined to speak to the media as he was still in shock. It is understood that his parents are on their way here.
The accident happened at around 11.45am at the junction of Bendemeer Road and Boon Keng Road.
It was not clear how Mr Kim, who was dressed in a blazer and described as having K-pop star looks, ended up under the truck.