The number of Virginia students taking challenging Advanced Placement classes has risen by nearly 60 percent over five years, a trend driven in part by the proliferation of AP courses offered through distance-learning programs.

In 2006, 44,816 public school students statewide took at least one AP exam, compared with 28,026 students in 2001, according to the College Board's recently released "AP Report to the Nation." AP participation rose at an even faster clip in Maryland, more than 100 percent, and in D.C. public schools, 80 percent, during the same period.

Virginia also joined a handful of other states, including Maryland, where more than 20 percent of graduating seniors scored high enough on an exam to earn college credit. The national rate was about 15 percent. Exams are scored on a five-point scale, and students can earn credit with a score of three or better.

With the Washington area known for its concentration of motivated high school students who aim for college-level coursework, Northern Virginia's school systems are helping to fuel the state's growth in AP participation.

Virginia Board of Education President Mark E. Emblidge said rising participation in AP classes shows that while the state is focused on helping all students reach minimum standards, teachers also are pushing them to excel.

"The great thing about this news . . . is there's a lot going on in schools to challenge kids who are going way beyond competence," Emblidge said recently in a conference call with reporters.

The "high-achieving students responsible for this good news are helping position the commonwealth for success in a global economy that demands a highly educated and motivated workforce," Gov. Timothy M. Kaine (D) said in a statement.

The College Board reported that 2.3 million AP tests were given in 2006 in 37 subjects. Nationwide, about 24 percent of 2006 high school graduates took at least one AP exam. In Virginia, nearly 33 percent of the state's 2006 public school graduates did.

In Virginia, public school students took 80,783 exams in 2006, nearly 14 percent more than in 2005. Some students take several AP courses each year.

The number of black students taking AP jumped about 82 percent since 2001, to 3,951. During the same period, the number of Hispanic students taking AP roughly doubled, to 2,310. The number of students from low-income families taking the tests also increased over five years.

State Superintendent of Public Instruction Billy K. Cannaday Jr. said research has shown that students who take an AP course, even if they don't earn one of the highest scores, are better prepared for college. He said schools encourage participation by allowing students to substitute AP tests for end-of-course Standards of Learning exams.

Cannaday said the launch of virtual AP classes in 2004 has allowed small and rural schools to offer a broader selection of classes online or via satellite. The distance-learning program includes English, government, biology and chemistry AP classes. Last fall, 2,147 students were enrolled in the virtual classes.

"While many schools may have AP courses, they may not have the range of AP courses young people would like to access," Cannaday said. "If you can't bring the teacher to the students, you bring the students to the teacher, no matter where they are."

The College Board recognized Thomas Jefferson High School for Science and Technology, an elite regional magnet school in Fairfax County that accepts students from several Northern Virginia jurisdictions, for impressive performance in calculus, chemistry, French, U.S. government and politics, and U.S. history.