After breaking the national under-14 boys' 1,500m freestyle record earlier this year, Glen Lim beat his own timing at the Singapura Finance 47th Singapore National Age Group (SNAG) Swimming Championships last night - marking a new personal best.

Clocking a time of 16min 36.38sec in one of the men's 1,500m timed finals, Glen bettered his initial mark of 16:39.73 set during a time trial in January.

Despite lowering the national age record by more than three seconds, the 13-year-old was still humble about his achievement.

"Setting a new record isn't actually a big feat for me. It is just a learning process," the Swimfast Aquatic Club swimmer said. "Breaking records is just to see where you have been."

Glen had also set a new 800m boys' freestyle mark in the Yakult February Time Trials with a time of 8:40.27, beating Sng Ju Wei's 22-year-old record of 8:43.07.

Hoping to qualify for the Junior Pan Pacific Championships in August through his timed final, Glen unfortunately missed out but was not deterred. "For the next meet, I'll try to aim for under 16:30," he said. "You have to believe in yourself and focus on the race."

The Raffles Institution student is looking forward to his next events in the SNAG Swimming Championships - the men's 200m freestyle and men's 400m freestyle.

Singapore swimming coach Gary Tan is glad there is an up-and-coming long-distance swimmer in Glen. "He's got many more years to really push the boundaries with the 1,500m that we've been trying to look for 1,500m swimmers since Teo Zhen Ren left the scene."

The 47th SNAG Swimming Championships kicked off last night at the OCBC Aquatic Centre at the Singapore Sports Hub and will continue until Sunday.