Core · Anti-extension
Flutter Kicks
Flutter kicks are a core exercise where you lie on your back with your legs a few inches off the floor and kick them up and down in small, quick alternating movements. The lower abs and hip flexors work to hold your legs up while your lower back stays flat.
Also known as: Scissor kicks, Flutter kick abs, Leg flutters
- Muscle group
- Core
- Movement pattern
- Anti-extension
- Type
- Isolation
- Equipment
- Bodyweight, Mat
- Difficulty
- Beginner
What muscles does the flutter kicks work?
Primary movers
- Rectus abdominis
- Hip flexors
Assisting muscles
- Obliques
- Transverse abdominis
- Quadriceps
The lower rectus abdominis and the hip flexors work hard to hold your straight legs off the floor. Because the legs move constantly, the work is sustained rather than explosive.
The obliques and transverse abdominis stabilise the pelvis so the lower back stays down. If your back lifts, the exercise has gone beyond what your core can control.
The quadriceps keep your legs straight and fatigue quickly. A burn in the thighs is normal.
Leg height sets the difficulty. Lower legs mean a longer lever and a harder exercise.
How to do the flutter kicks
Setup
- 1
Lie on your back on a mat, legs straight.
- 2
Place your hands under your glutes or beside your hips.
- 3
Press your lower back into the floor.
- 4
Lift both legs a few inches off the floor.
Execution
- 1
Kick one leg up while the other goes down.
- 2
Alternate legs in small, quick movements.
- 3
Keep your legs straight and your lower back down.
- 4
Raise your legs higher if your back starts to lift.
- 5
Breathe steadily throughout.
Common flutter kicks mistakes
Letting the lower back arch
The core stops controlling the pelvis and the back strains.
The fix: Raise your legs higher or place your hands under your glutes.
Bending the knees
It shortens the lever and reduces the demand.
The fix: Keep your legs straight, or raise them if needed.
Making big, swinging kicks
Momentum replaces core control.
The fix: Keep the movement small and controlled.
Holding your breath
It raises tension and ends the set early.
The fix: Breathe steadily through the set.
How many sets and reps?
| Goal | Sets | Reps | Load | Rest |
|---|---|---|---|---|
| Core endurance | 3 | 20–40 s | Bodyweight | 45–60 s |
| Progression | 3–4 | 30–45 s | Lower legs, no hands under glutes | 60 s |
| Beginner | 2–3 | 15–20 s | Higher legs, hands under glutes | 45–60 s |
Flutter kicks work well at the end of a session or as a station in a circuit. Count each kick as a rep, or time the set.
Running the flutter kicks in your next block? Hercules logs every set, shows last session's numbers before you lift, and suggests when to add weight.
Get it on Google PlayFlutter Kicks variations and alternatives
Dead Bugs
EasierA gentler anti-extension drill.
Leg Raises
AlternativeA slow, full-range version for the lower abs.
Reverse Crunch
AlternativeCurls the pelvis instead of holding the legs.
Hollow Body Hold
HarderA static full-body hold.
Bicycle Crunches
AlternativeAdds rotation and the upper abs.
Frequently asked questions
What do flutter kicks work?
The lower abs and hip flexors. The obliques and quadriceps also help.
Why does my lower back lift during flutter kicks?
Your legs are too low for your core strength. Raise them or put your hands under your glutes.
How long should I do flutter kicks?
Sets of 20 to 45 seconds.
Are flutter kicks the same as scissor kicks?
They are similar. Flutter kicks are up and down, scissor kicks cross the legs.
Hercules tracks every flutter kicks you log, shows you last session's numbers before you lift, and flags when your progress stalls.
Get it on Google Play