If you've ever tried to run at a high altitude, you know how low-oxygen environments can inhibit your performance. But speed skaters tend to perform better at high altitudes where less air resistance translates to faster speeds. At lower altitudes, skaters experience more drag, making it harder to set world or Olympic records.
The two graphs below show the connection between altitude and speed for Olympic speed skaters. The top graph shows results for gold medalist speed skaters. The bottom shows the host venue altitudes. Although speed skaters are growing consistently faster, there are clear spikes in performance at high altitude locations.