At the 2008 Summer Olympics, Berens won the gold medal in the men's 4×200-meter freestyle relay with Michael Phelps, Ryan Lochte, and Peter Vanderkaay, setting a new world record of 6:58.56. Berens swam the third leg in a relay split time of 1:46.29. Berens was the only member of the finals team to swim in the preliminary heats, posting a time of 1:45.47, just faster than Klete Keller's 1:45.51, to be selected to swim in the final.