Even before the Osim Sundown Marathon is flagged off tonight, many participants were already disgruntled by the long waiting time and lack of organisation when collecting their race packs at the F1 Pit Building since Tuesday.
Many of them posted their complaints on the marathon's Facebook page - from waiting times for up to three hours, to not having enough clear signs, to disorganised queues that had people drenched by the rain.
Language teacher Wen MacAlevey, 51, who has signed up for the half marathon for the first time, recounted that she took three hours to get her race pack on Wednesday.
She said: "Not only were the queues moving so slowly, but it was also crammed - we were standing shoulder-to-shoulder. It was suffocating in there and uncomfortable.
"By the time I left at 11pm, I felt so tired and because I was in my work attire of skirt and high heels, I got a blister on my right toe."
Teacher Soh Chung Wei, 40, who is planning to run a full marathon, said: "It was bad planning and a lack of crisis management."
The annual event, now into its 10th edition, is organised by HiVelocity and is expected to draw 27,600 participants across four categories this weekend.
HiVelocity's managing director Adrian Mok first posted an apology on the marathon's Facebook Page on Thursday, and he issued another apology yesterday night.
Not only were the queues moving so slowly, but it was also crammed - we were standing shoulder-to-shoulder. It was suffocating in there and uncomfortable.
WEN MACALEVEY, Sundown Marathon participant, on the massive queues at the race collection point.
He explained that the long waiting time was because there were insufficient printers on site to print the race bibs on the spot for each individual race-goer.
The practice at previous editions was to print all the bibs prior to the race pack collection period. However, as 20 per cent of them would end up being uncollected, the company wanted to reduce wastage by printing the bibs upon collection of race packs for this year's event.
But when the 20 additional printers Mok had ordered failed to arrive on time, HiVelocity could not cope with the load. That resulted in the lengthy queues.
He said: "The team had tested this system before at a smaller- scale event to good results, and we were confident of expanding the process to handle the larger crowd at Sundown.
"However, part of the shipment for these special printers to print the bibs could not arrive on time, resulting in us operating with a less-than-optimal capability."
They also tested a new system where participants could collect their race packs at vending machines located at four shopping centres - OneKM, Velocity@Novena Square, City Square Mall and Bukit Panjang Plaza.
But at 11am yesterday, the race organisers announced in a Facebook post that they have shut down the machines because they were also unable to cope with the demand.
Yesterday, organisers increased the number of collection points from 20 to 28 and the waiting time was reduced to 15 minutes.
Mok also added that, as a small token of the inconvenience they have caused, they would offer all runners free race photos.
While many were upset over how badly the problem was managed, some were sympathetic.
Eva Lim, who will be running the 42.195km full marathon, said she hopes that the race experience will make up for their shortcomings.
The director of an events management company, 39, said: "This has never happened before but I think people expected them to have a Plan B. But as long as he does well for the main part, everything (in the past) will be forgotten."