"Higher-risk settings" such as indoor gyms and indoor fitness or health studios will be closed and mass participation events will be suspended from Saturday to May 30 to minimise large Covid-19 cluster formation and reduce the risk of community transmission.
No spectators will be allowed at sports events during this period.
At a press conference yesterday, Education Minister Lawrence Wong, who co-chairs the multi-ministry task force tackling Covid-19, announced stricter measures to stop the spread of the disease in the wider community.
He said: "There are some settings which are of higher risk... typically where there is a high density of people who are unmasked and in close proximity with one another, often for prolonged periods.
A good example of such settings would be indoor gyms and fitness studios, he added.
The move comes as a blow to gym owners who previously had to cope with closures during the circuit breaker from April to June last year.
Mr Koh See Khiang, 44, owner of five Anytime Fitness franchises, was "bewildered" by the announcement: "It's not really clear to us why gyms have been singled out as high-risk. While I definitely appreciate the concerns around how people are working out in close proximity, I think the fitness industry in Singapore has proven that we're able to manage the safety measures and keep everyone safe, and there haven't been many people getting infected in a gym setting as far as I know."
Adding that this came "out of the blue", he said: "It's very difficult to plan without full visibility as to how long this would last. There's not enough information in front of us."
Gym-goers like Ms Claire Siew, who has been an Anytime Fitness member since 2019 and visits the gym five to six times a week, was also disheartened by the news.
While the 23-year-old accountant said she understood the rationale behind the move, she had hoped patron numbers would be limited instead of a closure of gyms.
She added: "It is not easy to replicate all the exercises outside the gym without gym equipment. I have some dumbbells and weights which I will use, and I will run and do more workouts at home. They are not a perfect replacement, but it's better than nothing."
Mass participation sport events will also be called off during this period. The OCBC Cycle Speedway Championships on May 29 will be postponed until further notice, although its May 15 to June 13 virtual rides will go on as planned.
The National School Games, which kicked off in March, will be suspended "to minimise intermingling of students across schools/institutions", said the Ministry of Education. It will monitor the situation and explore resumption of the remaining competitions when conditions permit.
Professional sports leagues and events like the Singapore Premier League (SPL) will be allowed to continue for now. The SPL's two fixtures on Saturday will proceed, but the decision to allow up to 250 fans in stadiums to watch matches live - which kicked in from April 10 - will now be rescinded.
Calling this an "unfortunate but necessary measure", Football Association of Singapore general secretary Yazeen Buhari said the league has decided all SPL matches "will be held without spectators indefinitely".
Lion City Sailors fan Jeremy Wong said: "It's disappointing because my friends and I have been enjoying recent SPL games at the stadiums, but the measures are understandable for the greater good and we will just make do with watching the games online."
Similarly, it is understood that the One Championship Empower event scheduled to take place at the Singapore Indoor Stadium on May 28 will be a closed-door event.