Exercise
ALTERNATING FLOOR LEG RAISE
Form cues
About
The Alternating Floor Leg Raise is a supine core exercise that trains hip flexor endurance and anti-extension strength by alternating legs while maintaining a pressed-flat lumbar spine. Because only one leg lowers at a time, the demand on the core is manageable for intermediate trainees while still building the strength needed to prevent lower back extension under distal loading — a key pattern for avoiding lumbar injury in both training and daily movement.
Instructions
Step-by-step technique
Lie flat on the floor
Lie face up on a flat surface with your arms extended by your sides and palms pressing firmly into the floor. Ensure your entire spine, especially the lumbar region, remains in contact with the ground throughout the movement.
Back flat against floorRaise and hover legs
Lift both legs off the ground simultaneously until they reach a 90-degree angle. From this position, lower one leg slowly until it is just a few inches above the floor, keeping the other leg extended straight upward.
Keep knees lockedMaintain core spinal tension
Engage your deep abdominal muscles to prevent your lower back from arching as you hold the extended position. If you feel your back lifting off the floor, bring your hovering leg higher to reduce the leverage.
Squeeze your absSwitch legs with control
Slowly sweep the hovering leg back to the 90-degree starting position while simultaneously lowering the opposite leg toward the floor. Maintain a steady, rhythmic pace, ensuring that both legs move with the same level of deliberate control.
Slow and steadyComplete your targeted repetitions
Continue alternating your legs until you reach the desired number of repetitions for your set. Focus on maximizing your range of motion without sacrificing the integrity of your flat-back position or compromising your form.
Focus on stabilityCommon mistakes
What goes wrong — and why
Lower back lifting from the floor
Allowing the lumbar spine to arch upward as the leg descends indicates the core cannot maintain neutral under the increasing moment arm.
Stop the range of motion before the back lifts. Only lower the leg as far as can be controlled with the back flat. Rebuild range progressively over weeks.
Holding tension in the neck and shoulders
Bracing with the upper body instead of the core is a compensation that adds tension where none is needed and reduces the focus on the intended muscles.
Let the arms rest relaxed at the sides. If the neck wants to lift, place one hand behind the head for support without pulling.
Lowering both legs simultaneously
Lowering both legs at the same time doubles the lever arm and moment, turning a manageable core exercise into one that almost always causes the lower back to arch in intermediate trainees.
Always alternate — one leg at a time. Treat this as a single-leg lowering exercise, not a bilateral one.
Variations · Progressions · Regressions
Adaptations for every level
Bent Knee Leg Raise
Bend the knee of the lowering leg to 90°, reducing the moment arm. Maintains the core training stimulus at a lower load.
Dead Bug
Add an arm movement opposite to the leg, extending it overhead. Increases the stability challenge while maintaining the same anti-extension principle.
Double Leg Lower
Lower both legs simultaneously from a raised position. Approximately twice the difficulty of the alternating version and requires full anti-extension strength.