More than 5,000 people ran, jumped and climbed through obstacles and trails on Saturday, near the Singapore Zoo.
Participants as young as six took part in the Singapore Night Trail race at Mandai, organised by Energizer Singapore.
It was split into six different events, including a 3km open obstacle race and an 18km trail race.
The obstacle courses saw participants climbing through hurdles made from string, and crawling under large nets.
The trail events had them running up and down slopes through the mud, thanks to the previous day's rain.
It is the fifth time the annual race has been held here.
The flag-off for the first event was at 3pm. The whole race ended at about 10.30pm.
The event is part of Energizer's global initiative to make a positive impact on the environment by supporting charities and spreading awareness as part of their corporate social responsibility programme.
Energizer Singapore also donated $11,000 to SportCares Foundation's beneficiary and youth ambassador, Mr Ashiq Arshad, in support of the foundation's sports programmes for the underprivileged and at-risk youth.
Mr Perry Sim, 38, a businessman, took part in the 3km parent-and-child obstacle race with his son, Aurelius, seven.
He said: "The obstacles were fun for the children, although they were too easy for the adults.
"But the distance was just nice. It took us less than an hour."
He said that his son cried because he was afraid of one of the obstacles at first.
But that did not stop them from enjoying themselves.
"It's a good event that not only allowed us to bond but also helped him overcome some of his fears.
"He said he wanted to come back again the next time. Hopefully, I can bring my other son as well," said Mr Sim.
Another participant, Mr Lim Lip Pheng, 48, an IT consultant, took part in the same event with his wife and son Joshua, nine.
He said: "It was a little bit of cross-country mixed with obstacles.
"We managed to clear everything, and we had a lot of fun.
"The morning after, the first thing Joshua said to me was 'I want to do it again'.
"So I guess we'll be back next year."
This article was first published on May 5, 2015.
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