An ab exercise with many names: the V-sit, Jackknife sit up, and Pike Crunch are all monikers for this challenging and effective move. 

A strength-based bodyweight resistance maneuver, the V-Up isolates your core to target the abdominals and obliques. Building strength in your back, this compound movement also works your hams and quads.

This fairly advanced level ab move wherein you create a V-shape hinge movement through the hip is not to be entered into lightly. If not performed correctly, it could lead to serious back, shoulder, and neck issues. 


In the fitness world, the origins of classic moves tend to be meticulously documented, while variations can be harder to accurately source. For reasons unknown, this does not hold true in the ab-work world. 

There is simply no record to be found of the first sit-up or crunch. We do know the crunch came later as a modified sit-up and that the latter has been a formal exercise since before the turn of the 20th century. 

Though the origins of the sit-up are hazy, the details of its subsequent demise are crystal clear.

One of the foremost back pain specialists on the globe and author of the acclaimed Back Mechanic, Dr, Stuart McGIl effectively ended the sit-up in the fitness realm with a single interview. 

In the 2016 Toronto Star article titled The Death of the Sit Up, he put the controversy surrounding the safety of sit-ups to rest once and for all. 

Questioned about the safety of practicing sit-ups for speed within fitness testing, McGill, who worked with the US National Institute for Occupational Safety and Health replied, “We measured the loads on the spine with each sit-up. [The spinal loads] were right on the limit noted by us as causing damage over time and with repetition.”

McGill then drove his message home loud and clear, remarking, “If [your goal] is to become faster, stronger, or if it’s to become injury resilient and have less pain in life and make yourself generally fit to enjoy life, then the answer is don’t do sit-ups.”

As a result, the US Military no longer administers sit-ups in their fitness testing. 

There you have it, folks. We are effectively excused from performing sit-ups ever again with a legitimate doctor’s note! 

Before you get carried away celebrating the death of the dreaded sit-up, we should let you know there are still several forms of safe ab work to take its place. 

Try to contain your relief. 

How to Perform a V-Up

Step 1: Lie face-up on a mat with your shoulder blades back, arms extended overhead, lower back pressed into the mat, and legs straight. 

Step 2: Engage your core as you synchronize the lift in your arms and legs, raising your upper torso off the mat until your lower back just leaves the mat.

Step 3: Slowly lower your legs and torso back down, maintaining control throughout your descent. 

Step 4: Repeat the process until your desired number of reps has been achieved. 


  • Improves coordination
  • Strengthens and stabilizes the core
  • improves balance and posture
  • Strengthens stabilizing muscles around the spine
  • Improves functional fitness
  • Flattens the midsection
  • Boosts metabolism
  • Strengthens abdominals
  • Increases oblique strength
  • Improves athletic performance


After you have mastered the basic V-up, here are some added challenges for you to try:

  • Hovering V-up: In this version, your feet never touch the floor.
  • Contact V-up: Lift your legs perpendicular to the floor and attempt to touch your toes with your fingertips.
  • Weighted V-up: Hold dumbells or strap on ankle weights for an added strength challenge.

Exercise Your Abs with Caution 

After murdering the sit-up, Dr. Stuard McGill did give us a few replacement exercises, noting that plank poses are both safer and better engage the entirety of the abdominal core. 

He also invented a safe crunch alternative which has been coined the McGill curl-up, which prevents the lumbar vertebrae from flexing during the movement.  By keeping one leg straight and placing both hands under the lower back, stress on the lower back is effectively minimized. 

The jury is still out on various crunch iterations such as the V-up. 

As with any new fitness regimen, consult your doctor before attempting this maneuver, and stop performing any abdominal exercise once it forces you to flex your lower spine.

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