China's Jiang Bo sliced another three seconds off the women's 5,000 metres world record in Shanghai yesterday, the second time in a week a new mark had been set in the event at the China National Games. Afterwards she thanked her controversial coach Ma Junren and said she was looking forward to the 2000 Olympics.

The 20-year-old Jiang clocked 14:28.09 in the final at the national games, beating the mark set by team-mate Dong Yanmei who clocked 14:31.27 on Tuesday.

Jiang's time of 14:31.30 in Tuesday's heats had also been inside the previous record of 14:36.45 set by Fernanda Ribeiro of Portugal in 1995.

Their performances catapulted Ma back into the international athletics limelight.

"Our coach Ma Junren uses a scientific method, and has already trained world champions," Jiang said after her stunning victory.

"Achieving this result today is a result of his experience," she said.

Ma's runners shot to fame earlier this decade by shattering middle distance records before the outspoken coach fell out with key team members and sport officials.

Sensational record-setting performances by his team in 1993 - including the 1,500, 3,000 and 10,000 metres at the Stuttgart world championships - led to accusations of drug use.

But Ma said his athletes' success was due to hard work and elixirs of turtle's blood and caterpillar fungus, and on Tuesday blamed western media for whipping up the drug-taking rumours. Jiang said no specific strategy for breaking the record had been devised by the coach.

"He just wanted the record broken, he didn't say which one of us, or how many of us should do it." Ma said after the heats on Tuesday that Jiang and Dong, 17, lacked experience but would be ready to take gold at the Sydney Olympics in 2000.

"I want to assure all the Chinese people that my runners can win at least three gold medals in the 2000 Sydney Olympic Games," he explained.