For time: ♀ 35-lb ruck, 20-in box ♂ 45-lb ruck, 20-in box The workout CHAD1000X is 1,000 step-ups for time, wearing a rucksack. It was a workout Chad created to train for a 23,000-foot climb in Argentina and that has taken the CrossFit community by storm due to the work and advocacy from The Step Up Foundation, a nonprofit created by Gold Star Spouse Sara Wilkinson.