Half a dozen world records were broken at the BIG 25 Berlin so far. It was a year ago, when Germany's oldest big city road race had its greatest day regarding winning times.
Both 25K world records were smashed. It remains a unique achievement in road running that the men's and the women's marks were improved in one race.
While Kenya's Sammy Kosgei clocked 1:11:50 his fellow countrywoman Mary Keitany finished with the first sub 1:20 time ever (1:19:53).
When the 31st edition will be started this Sunday fast times can again be expected. Adding a 10K and a 5x5K relay event around 10,000 runners are expected to take part in the BIG 25 Berlin.
Kenyans have dominated the event in the past decade, winning both the men's and the women's titles for ten years in a row.
Once again they will be the favourites on Sunday. One of the main contenders is 33 year-old William Kipsang, who celebrated his biggest win so far in 2008.
The Kenyan took the Rotterdam Marathon with 2:05:49. While he also won the marathons in Amsterdam (2003) and Seoul (2005) he will race the 25 k distance for the first time on Sunday.
William Kipsang will be up against an even faster marathon runner from Kenya.
Eliud Kiptanui made an astonishing breakthrough when he won the Prague Marathon a year ago with a course record of 2:05:39. He recently finished fourth in the Rotterdam Marathon with 2:09:04, suffering of stomach problems during the race.
Tujuba Beyu is the most likely runner to spoil the Kenyan party in Berlin. The Ethiopian has been entered with a half marathon best of 59:43 minutes.
Additionally he took the Rome Ostia half marathon this year with 59:58. But another one who has shown great form this season comes from Kenya again: Mathew Kisorio was fourth at the IAAF World Cross Country Championships in March. The 21 year-old then went on to take the Stramilano with 60:03.
The women's race will feature a former winner of the BIG 25 Berlin: Filomena Chepchirchir had taken the race in 2007 with 1:25:38.
A year later the Kenyan was second, although improving to 1:24:55. 29 year-old Filomena Chepchirchir showed fine form a couple of weeks ago. She won the Den Hague half marathon in a personal best of 69:06.
Her strongest opponents on Sunday will be fellow countrywomen: Eunice Kales, who was fourth a year ago in Berlin with 1:29:05, and Diana Chepkemoi. She has a half marathon personal best of 70:40 minutes.