The Kalsu WOD: Origins of the “Hardest Workout Ever”

By Kaitlin Bitz Candelaria | June 7, 2016
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When we put together our exhaustive list of hero WODs a while back, one of the first comments we got was that the list wasn’t complete because it didn’t include the Kalsu WOD.

RELATED: The Complete List of CrossFit Hero WODs

At the time, I was only vaguely familiar with Kalsu. After doing some research, I found that although the Kalsu WOD is not recognized by CrossFit HQ as an official hero WOD, it is recognized by many in the CrossFit community as one of the most difficult, if not the hardest workout they’ve ever come across.

What is the Kalsu WOD?

 For Time

100 thrusters (135/95 pounds)
 With 5 burpees EMOM

And you just thought 14.5/16.5 was bad Kalsu was programmed by ex-NFL player John Welbourn. After Welbourn retried from the NFL in 2009, he began dabbling in other projects including nutrition and CrossFit workout programs specifically designed to enhance football performance.

Wellbourn went on to establish CrossFit Football and Power Athlete HQ. Seven years ago, CrossFit Football programmed Kalsu and the rest is history.

To be fair, Wellbourn puts the blame for this horrendous workout squarely on shoulders of his associate, Andy Stumpf . You may recognize Stumpf’s name — he’s an ex-Navy Seal who’s also worked for CrossFit HQ. As if that wasn’t enough, his badass status is completely solidified by the fact that he’s also a sky-diver and base jumper. So, in case you can’t tell, Stumpf lives in a world of extremes, which is why it makes perfect sense that he programmed this workout. If you want to keep up with all the cool stuff he’s doing, check him out at @AndyStumpf212.

Wellbourn and CrossFit Football put the Kalsu WOD out in 2009 and it’s been breaking hearts and taking names ever since. The workout is notorious for its difficulty and has been called the hardest WOD ever by more than one person in CrossFit forums across the Internet.

Times range anywhere from the teens to upwards of fifty and sixty minutes to complete depending on your level of fitness, if you choose to scale and how quickly you can do burpees.

The true test in this workout is a test of mental toughness. Because the rep amounts are large and the burpees are frequent, it’s easy to get sucked into the black hole of mental despair during this WOD.

With a little hard work and a lot of grit, this workout is doable. However, it will not be fun.

Who is Kalsu?

You may have never heard of Bob Kalsu, but he’s definitely someone worth your attention.

Kalsu was an NFL player with an extremely promising career ahead of him. After starting the entire 1968 season with the Buffalo Bills as a guard, he was named Team Rookie of the Year.

Despite the promise of a legendary career, Kalsu put that aside to enlist in the Army in 1969 and was soon shipped out to Vietnam, where he lost his life less than a year later. Kalsu left behind a wife and two young children.

He was 25 years old when he died. The Kalsu WOD was created to honor Bob and his sacrifice for our country.

Kalsu WOD Variations

“Light Kalsu”
For Time

100 thrusters (135/95 pounds)
 With 3 burpees EMOM


“Don’t Let Go Kalsu”
For Time

100 thrusters (135/95 pounds)
 5 burpees each time you drop the bar


“Partner Kalsu”
For Time

100 thrusters (135/95 pounds)
 While the other partner does burpees, swapping as necessary


“Strongman Kalsu”
For Time — 30 Minute Cap

100 tire flips
 With 3 burpees EMOM


“Wallball Kalsu”
For Time

100 wall balls (20/14 pounds)
 With 5 burpees EMOM


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