Galen Rupp ran a personal best on Thursday in Zurich, which was the 5,000-meter race he had targeted at the start of the season for a big effort.

And Rupp, who believes he can run under 13 minutes, has now reached 13:07.35. There is still a ways to go. Alberto Salazar, who began coaching Rupp almost 10 years ago now, communicated from Europe that it was another rough close in Zurich.

“I just believe he needs to get stronger in order to utilize his speed at the end,” Salazar said. “I have focused so much on his speed, which was evident at the end of slow races, but in sub-13 pace races this year, he’s so tired by the end that he can’t used that speed to pick it up.”

It turns out, Rupp has averaged just 80 miles a week in 2010. He’s been in a lot of races, dating back to the indoor season, and because of that there were a lot of rest days built into his schedule.

Salazar believes in Rupp’s top-end speed. He came away from Zurich feeling that Rupp needs to boost his off-season miles and get stronger.

It’s all part of getting to the point where he can close 10Ks and 5Ks with long, sustained sprints the way the very top Kenyans and Ethiopians do. Chris Solinsky is doing a good job of it.

For 10 years, Salazar has constantly worked Rupp’s development as if it were a complicated, yet compelling, puzzle. Salazar’s knowledge — much of it culled from analyzing his own mistakes as a runner — has been paired with Rupp’s raw natural ability and desire for perfection. It’s a long-term project and Rupp, at 24, is getting better every year.

Next, Rupp may run a 1,500 in Lille on the 24th, or a 3,000 in Rieti on the 29th. Keep in mind, the race plan is apt to change at a moment’s notice.