Ultramarathon runners Yong Yuen Cheng and Lim Nghee Huat finally have the finish line in sight.
Today, they will run 50km for the 49th day in a row.
Tomorrow, they will attempt another 50km before they achieve what they started out on April 16 to do: run 50km for 50 days to celebrate Singapore's Golden Jubilee.
The men of iron will are hopeful that neither illness nor injury will steal their thunder now.
With their bodies continually under pressure for so many days, preventive measures were important, said Mr Yong, 43.
But despite warm-up stretches, ample hydration and paying attention to their strides, injury still caught up with them.
On the third day, for instance, Mr Lim, 62, tripped on a kerb and hurt his knee.
"It was a blow to fall down and hurt myself so early in the run," he said. A doctor gave him the assurance that he could go on and he healed in 10 days.
Mr Yong strained his Achilles tendon about 20 days into the feat. "The injury was hard to hide. People asked me to slow down or stop, but I am doing this for a greater cause," said Mr Yong, who had the help of a physiotherapist to continue.
"When you do something this long, you have to run from your heart. You have to get your body and mind to cooperate to overcome," said the former boxer.
Though the men are pushing their bodies to the limit, they have decades of running experience and are not reckless, said pacer Gerrard Lin, 31, who ran with them on every day but one.
Their times have ranged from five hours to nearly 10, depending on the difficulty of the route and their physical conditions.
Today, the public can see them off at 8am at the McDonald's outlet in Bishan- Ang Mo Kio Park, or be at the finish line at Fort Canning Park Carpark A at 3pm.
Tomorrow, the runners will start at 2am at Ion Orchard for the final run, ending at the Promontory at Marina Bay at about 10.30am.
There, they will perform a flame-kindling ceremony, harnessing the sun's rays to kindle the flame to be used in the SEA Games torch-lighting ceremony tomorrow night.
Runners can sign up to run in this final 50km leg but space is limited, organiser Heartware Network said.
To register to run the final leg, check www.facebook.com/go50sg. Runners are advised to be fit for a 50km run.