Sydney McLaughlin-Levrone redefined track's records. She's not finished.

Any list of the most dominant active American athletes isn't complete without a mention of Sydney McLaughlin-Levrone.

For nearly five years, the suspense of watching McLaughlin-Levrone race has hinged not on whether she will win, but whether she will break one of track and field’s records while doing it. McLaughlin-Levrone, 26, lowered the world record and won gold medals in her specialty, the 400-meter hurdles, so often and by so much that she eventually went looking for other challenges — and subsequently nearly set the world record in a new event this year, too.

At track's most recent world championships, on Sept. 15 McLaughlin-Levrone won the 400-meter world title while coming within .18 of a second of breaking its world record, which has stood for 40 years, too.

That versatility me