Defending champion Nao Kodaira of Japan leads the women's event at the ISU World Sprint Speed Skating Championships ©ISU

Defending champion Nao Kodaira of Japan leads the women's event at the International Skating Union (ISU) World Sprint Speed Skating Championships after day one in Heerenveen.

Kodaira won the women's first 500 metres race of the competition to get her title defence off to a strong start at the Thialf Ice Arena in the Dutch city.

She recorded a time of 37.27sec to finish first, ahead of compatriot Miho Takagi in 37.62 and Brittany Bowe of the United States in 37.89.

The Japanese skater then finished fourth in the 1,000m, in a time of 1:15.01.

Bowe took first place with a time of 1:14.82, while Takagi was second in 1:14.82.

Completing the podium was Russia's Daria Kachanova in 1:14.94.

Despite finishing outside of the top three, Kodaira's position was enough to establish her at the top of the standings with 74.775 points.

Takagi sits in second with 75.030 points, while Bowe is in third with 75.190 points.

In the men's competition, Russia's Pavel Kulizhnikov is leading with 68.770 points despite finishing third in both the 500m and 1,000m races. 

Japan's Tatsuya Shinhama won the 500m in 34.66, with Kai Verbij of The Netherlands in second with 34.72.

Kulizhnikov recorded a time of 34.74, joint with Håvard Holmefjord Lorentzen of Norway.

Kjeld Nuis of The Netherlands then won the 1,000m, recording a time of 1:07.86.

Japan's Masaya Yamada was in second with 1:08.03, while Kulizhnikov finished in 1:08.06.

Lorentzen is second in the overall rankings on 68.835 points, while Nuis is third with 68.910 points.

The competition will conclude tomorrow with the second men's and women's 500m and 1,000m races.