NAIROBI, Jan. 16 (Xinhua) -- Kenyan marathon champions Geoffrey Kirui and Betsy Saina are to race in this year's Kagawa Marugame International Half Marathon in Japan on 4 February, as part of their preparations for this year's Boston Marathon.

World marathon champion Kirui will be keen to test his speed in Marugame as he targets a return to the winner's podium in Boston, after giving best to Japan's Yuki Kawauchi last year.

"Each year presents a different challenge, and this season I want to work hard to reach the top and defend my title at the World Championships in Qatar," said Kirui.

"That campaign starts with the Kagawa Half Marathon and I believe it is an important step for me in preparation for the Boston Marathon."

Also competing in Kagawa is Napoli Half Marathon silver medalist Shadrack Kiplagat, along with fellow Kenyans Evans Cheruiyot and Edward Waweru, who won this race last year.

In the women's race, defending Kagawa Half Marathon champion Betsy Saina will be looking to build on her eighth place finish at the 2018 Frankfurt Marathon.

Saina won her first marathon last April on the streets of Paris, and will be returning to the United States aiming to win in Boston, where she had previously raced in the half marathon.

"I have my focus on the next race. I have just done my tempo workout and am happy for the progress attained. I am putting everything out to be ready for the Boston Marathon in April. I am thankful for the opportunity to race with the best in the world," said Saina on Wednesday.

Saina is one of several Kenyan runners eager to excel in 2019 to boost their chances of making the country's squad for the World Championships, which will be held in Doha, Qatar in October.