ex_KU6NUL

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Waist · Body Weight

Flat Knee Raise

intermediatestrengthMale & female model

Flat Knee Raise is an intermediate isolation strength exercise that works the abs (waist), with the hip flexors and obliques assisting. It needs no equipment beyond your own body weight. A typical prescription is 3 sets of 10-15 reps, and it burns about 5.5 calories per minute.

Target: Abs
Body part: Waist
Equipment: Body Weight
Category: Strength
Mechanic: Isolation
Force: Push
Sets × reps: 3 × 10-15
Calories / min: ≈ 5.5 kcal

Primary muscles

Core · Rectus Abdominis, Transversus Abdominis

Secondary muscles

Hip Flexors · Iliopsoas
Obliques · External Oblique, Internal Oblique

How to do Flat Knee Raise

Lie on your back with your knees bent and your feet flat on the floor. Place your hands lightly behind your head, and rest your head and shoulders against the floor.
Engage your core and lift both feet together, drawing your knees toward your chest while maintaining the bend in your legs.
Continue raising your knees until they are positioned above your abdomen, gently tilting your pelvis toward your ribs without lifting your upper back.
Slowly lower both legs until your feet return to the floor, maintaining control throughout the descent, then repeat for the desired number of repetitions.

Form tips

Support your head lightly without pulling on your neck with your hands.
Draw both knees upward together without swinging or using momentum.
Lower your feet slowly and touch the floor lightly before beginning the next repetition.
Exhale as you draw your knees toward your chest and inhale as you lower your feet.

Flat Knee Raise alternatives

Resistance Band Lying Bent Knee Raise

Abs · beginner

Resistance Band Lying Leg Raise

Abs · beginner

Bent Knee Lying Twist (On Stability Ball)

Abs · beginner

Crunch With Medicine Ball

Abs · intermediate

More abs exercises

Front Lever Raise

Abs · advanced

Hanging Oblique Knee Raise

Alternate Leg Raise

Bench Knee Tucks

Lying Leg Raise

Crunch Leg Raise

Bent Knee Lying Twist

Abs · beginner

Captains Chair Leg Raise

Abs · beginner

Flat Knee Raise FAQ

What muscles does Flat Knee Raise work?

Flat Knee Raise mainly works the abs in the waist (Rectus Abdominis and Transversus Abdominis). The hip flexors and obliques work as secondary muscles.

What equipment do you need for Flat Knee Raise?

None. Flat Knee Raise is a body weight exercise, so you can do it at home or anywhere with enough space.

How many sets and reps of Flat Knee Raise should I do?

Start with 3 sets of 10-15 reps. Pick a load or variation where the last one or two reps are hard but your form stays clean.

Is Flat Knee Raise good for beginners?

It's rated intermediate. Beginners can work up to it once they control simpler waist exercises.

How many calories does Flat Knee Raise burn?

About 5.5 calories per minute for a person of around 70 kg, based on a MET value of 4.5. Ten minutes of work is roughly 55 calories; heavier people burn more.

What is a good alternative to Flat Knee Raise?

Other exercises for the abs include Resistance Band Lying Bent Knee Raise, Resistance Band Lying Leg Raise, Bent Knee Lying Twist (On Stability Ball) and Crunch With Medicine Ball.

For developers

Use Flat Knee Raise in your app

Get this exercise and 1,900+ others from the WorkoutX API: 720p MP4 animations at 30 fps without the watermark, male and female models, muscles, instructions and form tips in 7 languages.

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# One request returns the exercise and its 720p media links
curl "https://api.workoutxapp.com/v2/exercises/ex_KU6NUL" \
  -H "X-WorkoutX-Key: YOUR_API_KEY"

{
  "id": "ex_KU6NUL",
  "name": "Flat Knee Raise",
  "model": "male",
  "counterpartId": "ex_JZA54A",
  "target": "Abs",
  "equipment": "Body Weight",
  "media": {
    "mp4": "https://…/ex_KU6NUL/mp4-720.mp4?…",
    "poster": "https://…/ex_KU6NUL/poster.jpg?…"
  }
}