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The Jackknife is a dynamic exercise that targets your core muscles, specifically your abdominals. This movement requires both strength and control, making it an effective exercise for shaping and toning your midsection. It also engages your hip flexors, lower back, and glutes, providing a full-body workout. To perform the Jackknife, you begin by lying flat on your back with your arms overhead and legs extended. As you lift both your upper body and legs off the ground simultaneously, you bring your arms and legs towards each other, forming a V shape with your body. This contraction of the abdominal muscles is what gives the exercise its name. The Jackknife can be modified to suit your fitness level and equipment availability. For beginners, you can perform a modified version by keeping your arms and/or legs slightly bent. As you progress, you can straighten your limbs for a more challenging workout. Additionally, you can try incorporating stability balls or resistance bands to further intensify the exercise. Including the Jackknife in your regular workout routine can help strengthen your core and improve your overall stability. Remember to engage your core throughout the movement and avoid using momentum to maintain control. As with any exercise, proper form is key to prevent injury and maximize your results. So be sure to consult with a fitness professional or watch instructional videos for a detailed guide on performing the Jackknife correctly.


  • Start by lying flat on your back on an exercise mat or the floor.
  • Extend your arms straight above your head so that they are perpendicular to the floor.
  • Keep your legs straight and together as you lift them up towards your chest.
  • At the same time, raise your upper body off the floor, reaching your hands towards your feet.
  • Engage your abdominal muscles to create a contraction in your core.
  • Pause briefly at the top of the movement.
  • Slowly lower your body back down to the starting position, keeping your legs and arms extended.
  • Repeat the movement for the desired number of repetitions.

Tips & Tricks

  • Focus on your core muscles while performing the JackKnife to maximize effectiveness.
  • Engage your abs and exhale as you lift your legs and torso up.
  • Keep your movements controlled and avoid using momentum to cheat.
  • Regularly stretch your hip flexors to improve flexibility for the JackKnife exercise.
  • Include other core exercises like planks and Russian twists to strengthen your midsection.
  • Maintain proper form throughout the exercise by keeping your back straight and shoulders relaxed.
  • Gradually increase the number of repetitions and sets as you build strength and endurance.
  • To challenge yourself further, hold a dumbbell or medicine ball while performing the JackKnife.
  • Stay consistent with your workouts and aim to incorporate the JackKnife exercise into your routine at least 2-3 times a week.
  • Listen to your body and rest if you experience any pain or discomfort.

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