Kenyans are good at running. Really, really good at running. Of the 86 medals they won at the Olympics, 79 came in various running events. (The other seven? Boxing. But we're not here to talk about boxing.)
Kenyans are not very good at swimming. With one exception: Jason Dunford.
Dunford is a pretty exceptional swimmer: he has held numerous African records, and even has a Commonwealth Games gold. (The Commonwealth Games are like the Olympics, but for countries that were once owned by Britain. This is how you ensure that Canada gets to win a bunch of medals.)
Dunford participated in the Olympics as well. He even held the Olympic record in the 100 meter butterfly, be it for a very brief moment. (It was taken away in the later heats and eventually passed on to some guy named Phelps.)
And, yes, (surprise, surprise!) Kenya's best swimmer of all time is Halachically Jewish.
We're willing to bet that distinction does not befall on any of its runners...