After two bouts of surgery, years of pain and countless setbacks, national triple jumper Stefan Tseng's athletic career has come to a stop.

The 25-year-old, still Singapore's best triple jumper despite falling short of his best in recent years, is retiring to focus on medical school, which begins next month.

While his decision was motivated mainly by studies, years of injuries also played a part.

"I've always had the passion. But it was the motivation to train," he told The Straits Times yesterday.

"I could possibly train during med school but it would take a lot to do it. I don't think I can ever be 100 per cent (again)... There's no point in pushing myself if I can't give 100 per cent."

Giving "100 per cent" meant yielding results that made Tseng one of Singapore's brightest sporting talents at one point. In 2007, he jumped 15.69m at the World Youth Championships in the Czech city of Ostrava to finish fourth, narrowly missing out on a bronze medal on countback.

At the 2009 Negri Sembilan Open, he became the first Singaporean man to surpass the 16m milestone, leaping 16.04m - a mark that is still a national Open and junior record.

But by his own admission, what followed those euphoric highs were only disheartening lows.

Tseng, who graduated from England's Loughborough University last year with a degree in human biology, had two operations in 2013 and 2014 to remove bone spurs from his right ankle.

He also suffers from congenital spondylolysis, a defect of part of the vertebra, a condition that has acquainted him with pain.

He said: "I was always trying to catch up... It eats at you and after a while it just gets demoralising, you get tired. You're always trying."

One setback after another put him further and further away from his best, while the ultimate dream of competing at the Olympic Games seemed increasingly likely to remain a dream.

For someone who placed among the world's best at youth level, and who was touted by many as a future world beater, discouragement simply turned into acceptance over time.

"Once you compete at that level and place even within the top eight (of the world), you get the feeling you can be up there if you train consistently," he said.

"I guess after a while I just got more and more demoralised and it didn't really matter.

"You can't even begin to think about something like the Olympics when you can't even get back to your peak.

"What I'm more disappointed in is not being at the top in at least the Asian level."

Still, finishing fifth with a jump of 15.52m at last June's SEA Games and 15.76m at last March's Singapore Open, Tseng is still by far the best triple jumper Singapore has to offer.

The Republic's other triple jumper at the SEA Games, 17-year-old Dylan Wong, posted 13.94m then.

Next month, Tseng will leave for Kuala Lumpur, where he will begin the first 21/2 years of his medical studies at the International Medical University, before another 21/2 years overseas, likely to be in Britain.

But he will return to Singapore often, especially because of KL's proximity, and is making himself available to help budding jumpers who might want his advice.

He said: "I've always wanted to give back to the sport that has given me so much. A lot of what I achieved helped open doors for me and I would definitely like to give back."