NAIROBI, March 15 (Xinhua) -- Kenya's Sammy Kitwara has warned his rivals that he intends to run a fast time on his debut at the Hamburg marathon on April 29.

The 31-year old had stomach pains in last week's Lisbon Half marathon, but he is certain he will overcome his problems in time for the marathon in Germany.

Speaking in Nairobi Thursday, Kitwara said he has no pressure to deliver the win and will run freely.

"If the weather conditions are right, I will try to improve my personal best of 2:04:28. I've heard a lot of good things about the Hamburg race and I'm really looking forward to it," he said.

In November of last year in Spain, he produced a 2:05:15 effort to finish almost a full minute inside the previous record, moving to seventh on the 2017 world list in the process.

It was Kitwara's first marathon win and also his first race to complete in 2017 having failed to finish his three other marathon attempts in Boston, Berlin and Amsterdam.

Now, Kitwara is dreaming of a fast time on his debut in Hamburg before turning his focus to the Berlin marathon later in the year.

However, he will face a stiff challenge from former world and Olympic marathon champion Stephen Kiprotich from Uganda, who wants to improve on his second-place finish from last year where he clocked in 2:07:31.

"Last year, the weather condition was bad. We had to battle with hail storms and the cold temperatures which, were dreadful but, on the other hand, the service provided for us athletes and the enthusiasm of the spectators was absolutely first class and very welcoming. That is why I'm very happy to be return to Hamburg. I want to improve on what I did last year," said Kiprotich, who trains in Kaptagat, near Eldoret.

Both Kitwara and Kiprotich competed at the Lisbon Half Marathon.