Exercise guide
Lying Alternate Straight Leg Circle
- Intermediate
- Isolation
- Rep-based
- Lower legs
This exercise targets the lower abdominals and obliques while improving hip mobility and quadriceps endurance through controlled rotational movement. It challenges core stability by requiring the torso to remain motionless while the leg moves through a wide range of motion.
Reviewed by the Crucible Fit team · Updated June 2026
Muscles worked
Setup
- Lie flat on your back on a mat with your legs fully extended and arms by your sides, palms facing down for stability.
- Press your lower back firmly into the floor to eliminate any arch and engage your deep core.
- Lift one leg approximately 45 degrees off the floor while keeping the other leg pinned to the ground with toes pointed.
How to do it
- Inhale and begin drawing a large, controlled circle with the lifted leg, moving it across the midline of your body first.
- Exhale as you sweep the leg out to the side and back up to the starting position in a smooth, continuous arc.
- Complete the circle over a 3-second tempo, then lower the leg and repeat the movement with the opposite leg.
- Continue alternating sides, ensuring the stationary leg and hips do not shift or tilt during the transition.
Form checklist
- Keep your lower back in constant contact with the floor to protect the spine.
- Ensure the stationary leg remains completely still and glued to the mat.
- Keep the moving leg as straight as possible by squeezing the quadriceps.
- Maintain a neutral neck by looking straight up at the ceiling.
Pro tips
- Focus on 'locking' your pelvis in place; the only movement should be the femur rotating within the hip socket.
- Imagine you are drawing the circle with your big toe to maximize the reach and engagement of the hip flexors and lower abs.
Make it harder
- Hover the 'stationary' leg 2 inches off the floor throughout the entire set to increase the isometric demand on the core.
- Increase the diameter of the circles to create a longer lever, significantly increasing the torque on the abdominals.
Frequently asked
- What muscles does the lying alternate straight leg circle work?
- The lying alternate straight leg circle primarily targets the abs and obliques, and also works the hamstrings as secondary muscles.
- What equipment do you need for the lying alternate straight leg circle?
- The lying alternate straight leg circle requires no equipment — just your body weight.
- Is the lying alternate straight leg circle good for beginners?
- The lying alternate straight leg circle is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.