-
GET INSTANT & CUSTOMIZED WORKOUTS FOR YOU
Find the best workout for my lifestyle.
-
VIEW OUR EXTENSIVE EXERCISE DATABASE
Discover new exercises to try at the gym and at home.
- Muscular Strength Exercises
- Romanian Deadlift
- Cardio Workouts
- Leg Press Machine
- Jumping Jacks
- Sumo Deadlift
- Power Clean
- Sumo Squat
- Glute Bridge
- Bicycle Crunches
- Bent Over Barbell Row
- Inverted Row
- Close Grip Bench Press
- Dumbbell Squat
- Seated Cable Row
- Benefits of Exercise
- Muscle Anatomy
- Decline Bench Press
- Barbell Bench Press
FAQ
Pricing
Login
Free Calorie Meal Plans & Metabolic Science
Is Your Metabolism Slow or "Stuck"?
Take our 60-second audit to see if hormonal resistance is blocking your results.
Prone Jackknife Crunch, V Sit Ups, Get My Free Fitness App
How to Do
How to Do Prone Crunch with a Jackknife V Sit Ups
The prone Crunch with a Jackknife v sit ups should begin with a good posture to avoid injury. Brace the spine by drawing your lower abdomen inward. Your core muscles should be activated to support your posture as you perform the exercise.
If any pain is experienced, immediately stop the prone Crunch with a Jackknife v sit ups.
Beginning
Beginning Crunch with a Jackknife
1. Begin by sitting on the ground in front of you with both feet on the floor.
2. Raise your feet off the floor by placing both hands behind your back, palms facing down.
3. Straighten your legs and squeeze your tummy to assist your abs engage. This is where you'll begin.
Movement
Crunch with a Jackknife Movement
1. Start by laying flat on the ground on your back, with your arms straight over your head, and your legs straight ahead with your toes pointing up.
2. From here, perform a crunch so that your arms come to your legs.
3. Bring your legs to your body, and your arms to your legs.
4. Come back down and repeat for repetitions.
Benefits
Crunch with a Jackknife Benefits
The upper and lower abdominal muscles, notably the transversus abdominis muscle, are strengthened by jackknife exercises.
Exercise Aliases
Jack Knife Crunch, How To Do Jackknives, Abs Workout.
Double Leg Reverse Crunches With Bent Knee Lying Leg Raises, Get My Free Fitness App
Plank Crunches Exercise, Get My Free Fitness App
Mountain Climbers Exercise, Get My Free Fitness App
Alternating Single Leg Reverse Crunch to Roller, Get My Free Fitness App
Alternating Straight Leg Reverse Crunch
Butterfly Crunch
Bench Leg Raises
Knee Bent Single Leg Reverse Crunch, Lying Leg Raises
Double Crunch
Bicycle Crunches
Full Body Crunch
Spiderman Crunches
Alternate Leg Crunches
V Crunches
Alternating Single Leg Reverse Crunch Lying Leg Raises
V Sit Crunch
Suitcase Crunch
Research Corner
📚 Coaching Delivers 4.73 lbs MORE Weight Loss
Research proves that combining coaching with app-based programs results in significantly greater weight loss than apps alone.
"You Can't Outrun a Bad Diet"
90% of obesity is driven by diet, not lack of movement. Your body has a "Metabolic Thermostat." When you exercise more, it burns less energy elsewhere to keep you stable.
This Plan is Generic. You Need Specific.
This sample menu works for an "average" person. But you aren't average. Your hormonal profile, weight history, and activity level require exact macro targets to work.
Get your personalized plan + 1-on-1 coaching to adjust it as you progress.
GET MY CUSTOM PLAN (SAVE $400)When paired with a human coach.
