GRAND RAPIDS (WZZM) -- Jennifer, Val, and Erin are into week nine of their CrossFit challenge.
They're using Benchmark WODs (workouts of the day) to keep track of their progress.
Benchmark WODs are standard groups of exercises, that often have women's names. They took on Jackie.
Greg Glassman, the founder and President of CrossFit explained why these workouts have women's names: "I want to explain the workout once and then give it a name. I thought that anything that left you flat on your back, looking up at the sky asking 'what just happened to me?' deserved a females name."
They'll do the same WOD again in about a month, to see how much they improve.