International mountain runner Scott McTaggart from Canberra has won the Sydney Tower Run-Up for the third consecutive year in a personal best time of seven minutes and 49 seconds.

Thirty-one year old Mr McTaggart wiped nine seconds off his 2006 Run-Up time to take out the top spot in 2008, winning a return flight to New York to compete in the Empire State Building race in February 2009.

More than 300 contestants took part in this year's 1,504-step vertical endurance race from Pitt St Mall to the tower's 250m-high Observation Deck, raising money for the Heart Foundation.

The fastest female runner was 25-year-old Jessamy Hosking, also from Canberra, who crossed the finish line in 9 mins and 29 secs. Ms Hosking also won a return flight to New York to compete in the Empire State Building race.

Hosking was the third-fastest female in the Run-Up in 2006 and 2007.

Sydney Tower marketing executive Jodie Crane said the Sydney Tower Run-Up was getting more popular each year.

"We're proud to be able to support the Heart Foundation this year and help get the message out to encourage Australians to be more active," she said.

At 305m, Sydney Tower is the city's tallest building. The fastest Tower Run-Up time recorded is six mins and 52 secs, set by Paul Crake in 2000.