Anyone who has done CrossFit for a while will tell you there’s no such thing as a good WOD. Some movements are more fun than others, depending on your skill set, but WODs are designed by nature to put you on your butt at the end.

RELATED: Meet the CrossFit Girls 

There will be some times in the midst of a WOD where you wonder what you’ve signed up for or whether or not you have the strength or discipline to keep going. Those feelings are pretty normal, especially for CrossFit beginners, and your mental fortitude grows over time.

However, there are some WODs that will always push you to your limit no matter how many times you’ve faced them. We’ve put together a list of the best WODs — or worst WODs, depending on how you look at it — to do exactly that.

Different workouts test different things and these ten WODs all attack you in different ways. Some require loads of endurance whereas others require fast and furious movements. Either way, these ten WODs will definitely challenge you.

Often referred to as the hardest WOD ever, Kalsu and its many variations has definitely left a bad taste in the mouth of CrossFit athletes all over the world…in the best way of course.

“Kalsu”
For Time

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

Kalsu is named for American football player Bob Kalsu. After being named Rookie of the Year in 1968 during his debut season with the Buffalo Bills, Kalsu enlisted in the Army and was killed in Vietnam. He was only 25 years old and left behind a wife and two young children.

Fran is possibly one of the most, if not THE most notorious of the CrossFit Girls. Like Kalsu, she can be performed in many different ways — you can check out our 15 favorite variations here, but be prepared. She’s going to hurt.

“Fran”
For Time

21-15-9
Thrusters (95/65 pounds)
Pull Ups

If you’re looking for a long-winded WOD, The Filthy Fifty is just that. Some of the most elite can knock this workout out in less than twenty minutes, but for most average people, this WOD takes anywhere from thirty minutes to an hour.

“The Filthy 50”
For Time

50 box jumps, 24-inch box
50 jumping pull-ups
50 kettlebell swings, 1 pood
50 walking lunges
50 knees to elbows
50 push presses, 45 pounds
50 back extensions
50 wall balls, 20 pound ball
50 burpees
50 double unders

Speaking of puke-worthy, Fight Gone Bad and its variations are enough to make you pray for a quick ending, even if it does mean encountering Pukey.

“Fight Gone Bad”
AMRAP

3 rounds of Max Reps
Wall-ball, 20-pound ball, 10-foot target
Sumo deadlift high-pull, 75 pounds
Box jumps, 20-inch box
Push press, 75 pounds
Calorie row

In this workout you move from each of five stations after a minute.The clock does not reset or stop between exercises. This is a five-minute round from which a one-minute break is allowed before repeating. On call of “rotate”, the athletes must move to next station immediately for best score. One point is given for each rep, except on the rower where each calorie is one point.

Oh, Murph. Everyone’s favorite hero WOD, Murph is traditionally performed on patriotic holidays like Memorial Day and July 4. It has all the proper makings of a hero WOD — it’s long, it’s grueling and it’s painful.

“Murph”
For Time

1 mile run
100 pull-ups
200 push-ups
300 squats
1 mile run

This workout can be done straight through or partitioned. To be considered RX, the workout must be performed while wearing a 20-pound weight vest.

The workout is done in honor and memory of Navy Lt. Michael Murphy, 29, of Patchogue, New York, who was killed in Afghanistan on June 28, 2005.

No one was sad to see 14.5 go at the completion of the 2014 Open. In fact, I heard some say that they would absolutely, under no condition, ever complete the WOD again. So of course, Dave Castro announces the same WOD for 16.5 — the man loves to prove a point. With gritted teeth, the CrossFit community once again tackled this nasty combination of thrusters and burpees and prayed that Castro would finally retire the workout back to hell where it belongs.

“14.5/16.5”
For Time

21-18-15-12-9-6-3
Thrusters (95/65 pounds)
Bar-facing burpees

In 2009, athletes at the fourth CrossFit Games were asked to do a 7K trail run at the Ranch, home of Games director Dave Castro in Aromas, California. Some Games athletes were quoted as saying it was the worst workout they’d ever done.

So again, in true Dave Castro-fashion, the 2016 CrossFit Games opened with an even more difficult 7K trail run on the Ranch, which included lots of sun and lots of steep hills. Many of the athletes took on the trail wearing tactical pants and gloves and spent a lot of the event sliding and climbing as opposed to simply running.

“7K”
For Time

Do your best to find a trail comparable to the Ranch

Do you have a hard time choosing between weightlifting and cardio? This WOD may be just what you’re looking for.

The Inman Mile is difficult, if not impossible, for many CrossFit athletes. Scale your weight accordingly and complete as much of the mile as possible.

“Inman Mile”
For Time

From the U.S. All-Round Weightlifting Association, USAWA: “The lifter will have loaded onto his/her shoulders a weight equal to 150 percent of bodyweight. The lifter will then carry the weight a distance of one mile. Gait is optional. Resting is allowed, but neither the lifter nor the weight may be supported. Records will be kept in both pounds and time. Should the weight be touched by any aide once the lift has begun, the event is terminated. The lifter may be handed refreshments during the lift.”

Nothing to inspire a little Christmas joy like dying on your box floor. The 12 Days of Christmas WOD is definitely not for the faint-hearted, as it demands hundreds of grueling reps to complete.

“12 Days of Christmas”
For Time

1 clean and jerk (225/150 pounds)
2 muscle ups
3 box jumps (30/24 inches)
4 hang squat snatches (115/75 pounds)
5 bar facing burpees
6 push presses (115/75 pounds)
7 pistols
8 toes to bar
9 wall balls (20/14 pounds)
10 chest to bar pull ups
11 HSPU
12 front squats (225/150 pounds)

Round 1 — 1 clean and jerk
Round 2 — 2 muscle ups, 1 clean and jerk
Round 3 — 3 box jumps, 2 muscle ups, 1 clean and jerk
And so on

Is lifting your favorite thing? The Air Force WOD combines lifting and cardio — cardio in the sense that you’re stimulating your cardiovascular system by lifting weights as quickly as possible. This WOD is similar to Kalsu with burpees every minute on the minute.

“Air Force”
For Time

20 thrusters (95/65 pounds)
20 sumo deadlift high pulls (95/65 pounds)
20 push jerks (95/65 pounds)
20 OHS (95/65 pounds)
20 front squats (95/65 pounds)
4 burpees EMOM
WOD starts with Burpees