Andy Lyons / Getty Images For some of us, the Olympics don't really get started until the runners take the starting line and the javelins go flying. Every four years — or in this case, five — we rejoice when the hours of swimming coverage give way to wall-to-wall athletics, as the Olympics and other countries call track and field. Here are a few storylines to watch for, as the tracksters lace up their spikes and events kick off in Japan. JuVaughn Harrison is a double-threat jumper JuVaughn Harrison won both the high jump and the long jump at the U.S. Olympic trials last month. That means the 22-year-old will compete in both events in Tokyo, making him the first man to represent the U.S. in both events at the Olympics since Jim Thorpe in 1912.