SINGAPORE - Leg and back cramps reduced Hu Xiu Ying to walking pace in the last 6km of the Osim Sundown Marathon early yesterday morning but, even as she was repeatedly asked if she needed medical assistance, the 39-year-old persisted as she wanted to complete the 42.195km race.

Her time of 3hr 35min 50sec was slower than her three and a half hour effort last year, but it was enough for her to finish as the top female full marathon runner.

The China-born Singaporean, who received her citizenship last July, was second last year on her Sundown Marathon debut.

"I'm not very satisfied (this time) because if I didn't cramp at the back, even if I had run slowly, my pace was still at around 3:20, which was my target," said Hu.

"This year I wanted to try my best to finish in first place but my target has always been the timing... I hope I can do better."

She turned professional at the tender age of 13 and represented China until the age of 22. After retiring from the national team, she spent six years as a coach in Taiwan before taking a 10-year hiatus to look after her children.

At 39, she acknowledged that she has only a few years left in competitive running. In a bid to clock faster times and improve her chances to represent Singapore at next year's SEA Games in the Philippines, Hu will leave for China on Saturday for a three-week training stint with the Chinese national team.

"I was thinking last year that after my children grow up, I still can run and I want to inspire the younger generation," said the freelance running coach, whose daughters are aged 10 and seven.

"As a mother, I think I still can run and the younger runners can do better than me... I still want to be a full-time coach to help others achieve their best, and the younger generation has a long way to go."

Both Hu and Kenya's John Muiruri Mburu, who won the men's marathon in 2:29:07, took home $500 for their wins.

This year's Sundown Marathon attracted 25,500 participants across four categories: 5km, 10km, half marathon and full marathon. The 5km, 10km and half marathon races were flagged off at the F1 Pit Building on Saturday night, while the full marathon started at 1am yesterday and finished near the Singapore Flyer.

Now into its 11th edition, this year's event saw an improved race pack collection system, including more counters and extended time.

Last year, there were hiccups in the process, which led to participants complaining that they had to queue outdoors for several hours.

This year's improvement drew praise from returning participant Kevin Simon, who took part in the 10km race last year.

The 27-year-old naval diver, who competed in the half marathon this year, said: "(A highlight of the race) was the flag-off, which had a DJ playing music.

First-time participant Pang Ling Li also enjoyed her 21.1km race.

"I like the route as it's clearer compared to other races. From my previous experiences, sometimes the signage is not clear... and this could confuse the runners," said the 33-year-old.

Hu noted that conditions were warmer this year compared to last year's event in March.

"I hope next year the organisers can consider holding it in March again, because Singapore is really too hot," she said, while adding that the past few days of rain had made it cooler.

"Everything else was pretty good, other races are usually early in the morning and it's special to run during the night."