SINGAPORE — It looks like national marathoner Mok Ying Ren’s decision to take a month’s no-pay leave to train in Japan in preparation for next month’s SEA Games is paying off handsomely.

Last month, the 25-year-old doctor recorded a new personal best (PB) of 31min 55.55sec in the 10,000m at the Nittaidai Sports University’s time trials.

He added another feather to his cap yesterday when he recorded a new national half-marathon mark at the Ageo City Half Marathon in Saitama. He clocked 1hr 7min 53sec to break his own national mark of 1:08.18, which he set in 2011 at the Bareno Run in Kuala Lumpur.

That is not all — Mok, who finished 300th in the 8,000-strong international field, also ended up going under the qualifying time of 1:10.00 for next year’s World Half-Marathon Championships, which will be held in Denmark in March.

In a telephone interview, Mok, who spent the last month training with Asian Duathlon champion Yuya Fukaura, said he was pleased with his results even though he did not achieve his aim of breaking two national records.

“I came to Japan on a one-month no-pay leave to break two records but, unfortunately, the first one did not come true,” said Mok whose PB in the 10,000m was about 36sec off P C Suppiah’s 40-year national mark of 31:19.00.

“But I am happy because it (the new national record) is a huge feat and it builds me up nicely for the year-end SEA Games, which is special to me because I have been aiming to go for it, but did not make it in the past two editions. During my time here, my fitness has been good and is peaking. I also got a few tips from Yuya, so I am happy.”

Mok, who won the triathlon at the 2007 SEA Games in Thailand, did not qualify for the 5,000m and 10,000m for the 2009 Games. Two years later, he pulled out of the 2011 SEA Games after qualifying for the 5,000m because of a foot injury.

According to the self-trained runner, who is also aiming to qualify for the marathon at the 2016 Rio Olympics, what really boosted his confidence yesterday was his pace.

“Halfway through my run, I felt like I was going at a really fast pace that I had never been having before, and I was thinking, maybe, this will be a new personal best and a national record,” said Mok, who clocked a new PB of 2:26.30 at the Gold Coast Marathon in July to qualify for the SEA Games and put himself in medal contention in Myanmar (the 2011 SEA Games marathon gold was won by Indonesia’s Yuhuza in 2:27.45).

However, he now has to figure out how he can taper his training for the Games while doing his national service.

Said Mok, whose marathon event is in December: “I will be enlisting for the medical officer conversion course on Dec 2 and will be booking out for three days to participate in the SEA Games.

“So, I will have to taper my training while at the course. That is the challenge now.”