"Double-unders require the athlete to propel the body upward and lift the feet up to several inches from the ground while making small, fast circular movements with the wrists in order to execute multiple turns of the rope with each jump. They develop dynamic balance, speed, quickness, agility, coordination, concentration, and cardiorespiratory efficiency." —Buddy Lee, "Jump Rope Basics, Part 2" (adapted)
WatchThe Double-UnderWatch the workout announcements from Australia and Germany on the CrossFit Games site.
Analysis opens our minds and more importantly opens our eyes. We cannot, yet, derive fundamental principles more valuable than measure, think and experiment. The better part of measurement may lie in knowing what we are doing, so that we can do something different.
In this series, Professor Tim Noakes, author of Lore of Running and Waterlogged, presents the science and history of hyponatremia. He explores how overdrinking during exercise became the greatest threat to the health of endurance athletes — a crisis driven in no small part by the commercial objectives of the sports drink industry.
Read MoreThe Hyponatremia of Exercise, Part 1