The Kalsu WoD: Goal Times, Tips, and Safety

A man performs a front squat in a CrossFit gym

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Many people who are invested in the fitness world in some way or another—CrossFitters and non-CrossFitters alike—know about the CrossFit Hero WoDs (workouts of the day). This special collection of CrossFit workouts comprises insanely challenging, unique WoDs that were designed in remembrance of a fallen hero. 

CrossFit Hero WoDs honor men and women who died in the line of action while serving in the armed forces, law enforcement, emergency medical services, and fire rescue. The intention is to pay tribute to these fallen heroes by putting yourself through hard physical work. 

The CrossFit “Kalsu” WoD is one that often appears at lists of “top hardest CrossFit hero workouts.” The workout honors 1st Lt. James Robert Kalsu, 11th Artillery Regiment, 101st Airborne Division, U.S. Army, who died in action on July 21, 1970 in the Ashau Valley in Vietnam.

was also an All-American offensive tackle in the National Football League, playing with the Buffalo Bills for one season. He declined a deferment offer to continue playing professional football, and instead decided to serve his country in the Vietnam War.

The CrossFit hero “Kalsu” WoD is as follows:

  • 100 thrusters for time (135 pounds for men, 95 pounds for women) 
  • Start with five burpees and complete five burpees at the top of every minute

The "Kalsu" CrossFit Hero WoD

Score: Your score is the total time it takes to complete all 100 thrusters.

Goal Times: Beginner: 22-30 minutes. Intermediate: 19-22 minutes. Advanced: 15-19 minutes. Elite: <14 minutes 

Equipment Needed: Barbell, bumper plates

Level: This WoD is extremely challenging but suitable or scalable for all fitness levels.


This challenging workout isn't just for show; here are some of the benefits gained from completing the Kalsu WoD.

Endurance and Stamina

With a workout like the Kalsu WoD, there’s nothing to it but to do it. Seriously, you just kind of have to get over the intimidation and go for it. Luckily, you’ll reap some benefits of your intrepidity—the primary two being endurance and stamina

You can probably infer that the Kalsu WoD promotes endurance just by the sheer number of reps. You must complete 100 thrusters, and that alone is enough to incite a serious muscle burn. Now add in five burpees at the top of every minute: if the workout takes you 20 minutes, that’s 100 burpees. 

This WoD is all about how long you can keep moving under tension. 

Overhead and Hip Mobility

The main movement in the Kalsu WoD—the barbell thruster—requires a good range of motion in the hips, shoulders, and thoracic spine. While it's best to have the requisite mobility before attempting thrusters, performing them correctly with your current range of motion (e.g., half-squatting instead of squatting to full depth so your torso doesn't collapse) can enable you to still get a great workout as you continue to improve your range of motion with mobility work, foam rolling, and stretching.

Mental Grit

The Kalsu WoD is just as much a mental challenge as it is a physical one. Just looking at the workout can evoke shudders. This workout requires you to intentionally push your limits, to look for the end range of how much work your body can handle. And it requires you to stay near that limit the entire time.

Step-by-Step Instructions

For the Kalsu WoD, all you need is a barbell and some bumper plates. For men, the prescribed weight of 135 pounds means you need a 45-pound barbell and two 45-pound plates. For women, the prescribed weight of 95 pounds means you need a 35-pound bar, two 25-pound plates, and two 5-pound plates. Make sure to clip your weights onto the barbell so they don’t slide off, especially if you tend to drop the barbell from overhead. 

How the Kalsu WoD Works

When the clock starts, you’ll begin with five burpees. Then, you’ll immediately move to the barbell and start performing thrusters. You’ll perform thrusters until the top of the next minute, at which point you’ll do five more burpees. This cycle continues until you complete 100 thrusters.

Most CrossFit trainers will recommend that you put the barbell down at five to 10 seconds before the next minute, in an attempt to give yourself some transition time.

A good tip is to choose a number of thrusters you’ll do every minute, no matter how much your muscles and lungs burn. For example, if you can stick to five thrusters each minute, you’ll finish the workout in 20 minutes, which is a great score.

How to Do Thrusters 

The thruster is a complex movement that blends two separate exercises—the front squat and the overhead press—into one seamless flow. Here’s how to do it: 

  1. Stand with the barbell in the front rack position (you’ll need to power clean it to get to this point). Elbows point forward; triceps hover parallel with the ground; core becomes engaged; eyes look straight ahead.
  2. Push your hips backward and bend your knees to initiate the squat descent. Keep your heels flat on the floor and don’t let your elbows fall. Descend until you reach the end of your range of motion, which may be at parallel, below parallel, or slightly above parallel. 
  3. Drive through your heels and stand up. As you come out of the squat, forcefully squeeze your glutes and thrust your hips forward into a full extension.
  4. The press: Once you reach full extension of the hips, press the barbell overhead. Once you lock out your elbows, the rep is complete. Make sure you don’t overextend your back in this portion of the thruster—keep your spine neutral and core tight.
  5. The return: After you lock out overhead, carefully return the barbell to the front-rack position. Bend your knees to absorb some of the shock and avoid bruising your collarbone. You can descend directly into another rep, or take a second to reset and reposition yourself. 

How to Do Burpees

Gotta love burpees, right? Don’t worry, we know the real answer: burpees kind of suck. But, at the same time, they’re kind of fun. Anyway, here’s how to do them: 

  1. Start standing with your feet about shoulder-width apart.
  2. Bend at the hips and the knees, bringing your palms to the floor. 
  3. Kick your feet out behind you to land in the high plank position.
  4. Lower your body to the ground and push back up (AKA, perform a push-up). You may lower your entire torso to the ground if a traditional push-up is too difficult. 
  5. Once you’re back into the high plank position, jump your feet forward so that they land right outside of your hands. 
  6. Stand up straight and do a little jump with your arms above your head. 

Common Mistakes

Even though you're only performing two moves, there is still the potential for error. Here are some of the most common mistakes, and how to avoid them.

Going Too Fast, Too Soon

Hold your horses: You may be excited about the Kalsu WoD and want to go all out, but that’s not the best strategy (it might be the worst). Instead of trying to make this workout as intense as possible, try to pace yourself. 

Pick a number of thrusters you know you can complete every minute even when you’re tired—the number of reps should be challenging, but doable. You want the first two to three sets to feel moderately easy, because trust us, it’s going to get really hard, really quickly.

Using a Weight That’s Too Heavy 

Don’t let your ego get the best of you. The prescribed weights for the Kalsu WoD are heavy even for advanced CrossFitters. There’s no shame in scaling! In fact, scaling appropriately means you preserve the intended stimulus of the workout, which in the case of Kalsu, is to move relatively quickly. 

Technique Mistakes

Because the thruster is such a complex movement, it comes with a lot of potential mistakes. Some of the most common thruster mistakes include:

  • Poor front rack position: Your core isn’t engaged, your elbows point too low, or your torso hyperextends. 
  • Limited squat mobility: Your torso leans too far forward during the descent, your heels raise off the ground, or your knees cave in. 
  • Lack of full extension: On the ascent, you don’t fully extend your hips and legs. 
  • Limited overhead mobility: You can’t press the barbell overhead or lock out your elbows because of shoulder or spinal range of motion. 

There’s a common theme for all of these mistakes, which is limited mobility. You can get better at thrusters by practicing mobility drills for your ankles, hips, upper spine, and shoulders. Plus, incorporating mobility into your regular training regimen will help you improve overall because your body will be able to access deeper ranges of motion. 

Modifications and Variations

There’s always an opportunity to modify (or, in CrossFit lingo, scale) a workout to your current fitness level. In fact, much of the CrossFit methodology was built upon the foundational concept that everyone should train the same movement patterns—but the exact exercise and load will differ based on fitness level and life status (i.e., age, pregnancy, etc.). That said, here are some easy ways to modify the Kalsu WoD to match your abilities. 

Reduce the Weight 

As long as no injuries are present, the first consideration should always be to reduce the weight. This way, you preserve the movement and the stimulus (in this case, thrusters and volume). You may need to reduce the weight by many pounds or as little as five pounds to complete all of the reps—either way, that’s okay!

Front Squats

If you struggle with a limited overhead range of motion, especially due to an injury, you can substitute thrusters with front squats. You’ll simply eliminate the pressing portion of the movement. 

Half-Burpees (or Up-Downs)

Some people may feel uncomfortable with a full burpee, either because the push-up portion is too difficult, or because of a life condition, such as pregnancy (it’s definitely not recommended that pregnant women perform CrossFit-style burpees). 

If this is the case for you, try half-burpees (also called up-downs or simply no-push-up burpees) instead. To perform these, you’ll follow the above steps for a burpee, but leave out the push-up portion: As soon as you kick your feet out, jump them back in and stand up to complete the rep.

Safety and Precautions

Always take care to prepare for a workout. Some special precautions you should take before beginning the Kalsu WoD include: 

  • Clip your barbells. Use barbell clips that are snug—they shouldn’t slip or slide and should keep your bumper plates locked into place. 
  • Don’t drop the barbell from overhead. This puts you and others at risk for injury. Lower your barbell to the ground with control every time you finish a set of thrusters. 
  • Make sure you have enough space to work out. Clearly designate your area and ask others to create more space if you feel they are too close.

And then there are some general fitness safety measures to keep in mind: 

  • Make sure you’re hydrated and fed before attempting this workout. The Kalsu WoD can be a long one (more than 30 minutes in many cases), so you definitely want to avoid mid-workout hunger or dehydration. 
  • Wear proper footwear. Your shoes should be durable and sturdy, and they should fit well. Running shoes aren’t the best choice for a WoD like Kalsu, because they can contribute to ankle instability. Instead, choose a shoe with a flat sole and wider toe box to help keep your heels on the ground and your feet stable.
  • Warm up to prepare your muscles and joints for exercise. Diving directly into an intense workout like the Kalsu WoD without a warmup can be a recipe for injury. Research shows that a proper warm-up can increase blood flow and muscle temperature, which contributes to improved workout performance and reduced risk of injury.
  • Spend some time cooling down with stretches or other recovery tactics, such as foam rolling. While research on the beneficial effects of cooling down is limited, you probably know from your own anecdotal evidence that you feel better the day following a workout if you stretch afterward.
2 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Park HK, Jung MK, Park E, et al. The effect of warm-ups with stretching on the isokinetic moments of collegiate men. J Exerc Rehabil. 2018;14(1):78-82.

  2. Van hooren B, Peake JM. Do We Need a Cool-Down After Exercise? A Narrative Review of the Psychophysiological Effects and the Effects on Performance, Injuries and the Long-Term Adaptive Response. Sports Med. 2018;48(7):1575-1595.

Additional Reading

By Amanda Capritto, ACE-CPT, INHC
Amanda Capritto, ACE-CPT, INHC, is an advocate for simple health and wellness. She writes about nutrition, exercise and overall well-being.