Sprint coach Rohsaan Griffin puts his "future Olympians" through their paces. [Photo by Gao Erqiang/shanghai star]

"They were stuck in the old East German bloc mentality of training. They believed in heavy weights, long slow workouts, no rest days. But this didn't reflect how the sport has evolved," he says.

"On the other hand, the girls were coming to practice and not giving it 100 percent, because they didn't think they had to. They thought they had all the time in the world, so mentally, the approach had to evolve. They had to step it up."

He turns up at a Starbucks on Halloween in horn-rimmed glasses and a black Nike t-shirt covered in ghoulish figures. He used to run the same signature event as Usain Bolt and has the same wraparound smile, but not the centaur-like stature.

He also lacks the strapping shoulders and pumped arms of power runners like Johnson, whose indoor US record he snatched in 1999 by clocking 20: 32.

"It was one of the fastest times ever run, worldwide," he said. "I ran an outdoor time indoors. That is why it took so long for me to break and for Wallace (Spearmon) to break (six years later)."

The indoor event is slower and more tactical than the outdoor race as it is run over a shorter, banked track that he light-heartedly compares to a velodrome.

Now Griffin aims to rewrite China's sporting history. Apart from a few throwers and endurance runners, Chinese women have made little impact in track and field.

At the 2012 London Olympics, female discus-thrower Li Yanfeng earned the country's sole silver in T&F, while the only gold came from men’s 20km racewalker Chen Ding, who also managed to set an Olympic record.

But China has a precedent for success at the sport's blue-ribbon event courtesy of Taiwan-born Chi Cheng. A former hurdler, she repeatedly reset the world record in the 100m sprint in the late 1960s and early 1970s.

As the Shanghai school's new assistant sprints and hurdles coach, Griffin spends most of his time "tuning up his race cars," as he affectionately refers to his young wards. He also acts as their physiotherapist.

In his downtime, he likes chatting to Liu Xiang, China's poster boy for track and field.

"I sit next to him at lunch. We talk about sneakers and cars. Nothing ever related to track and field," he says.

The ongoing program is being overseen by Dan Pfaff, a colossus in the world of track and field coaching who has been mentoring Griffin.

"The school wanted something different, and they knew Dan had worked with so many great athletes, from Donovan Bailey to Steve Louis," he says. "They wanted something streamlined, not lots of pockets of different philosophies."