The iron cross here is the floor exercise, not the gymnastics hold on rings: you lie on your back with your arms out in a T and take one straight leg across your body toward the opposite hand, then back, then the other leg. Your shoulders stay pinned while your hips rotate underneath them, which trains the obliques and lower back through a twist almost nothing else in a gym routine asks for. Done light it is a common warm-up; done slowly with a pause, it is a proper core exercise.
How to do it
- Lie on your back, arms out in a T with the palms pressing into the floor, legs straight.
- Lift one straight leg and take it across toward the opposite hand while both shoulders stay down.
- Bring it back to the middle under control, then switch legs.
Common mistakes
- Letting the opposite shoulder lift off the floor to reach further.
- Throwing the leg across and letting it crash back down.
What it trains
- Obliques
- rotate the pelvis under the ribcage to take the leg across, then pull it back to the middle
- Lower back
- keep the spine long and steady as it twists
- Abs
- keep the lower back from arching as the straight leg lifts
- Hip flexors
- raise the straight leg off the floor at the start of each rep
Variations and alternatives
Common questions
Is this the same as the iron cross on rings?
Only in name. The gymnastics iron cross is a hold on the rings with the arms straight out to the sides, one of the hardest strength skills in the sport. This exercise gets its name from the T your arms make on the floor, and anyone can do it on a mat.
Do I log both sides?
No — log the reps of one side, not the total. Eight to each side goes in as 8, which keeps your sets comparable, and StackUp progresses your target reps from that per-side number.
Should I swing the leg or move it slowly?
Slowly enough that both shoulders stay on the floor. A light swing is fine as a warm-up, but then momentum does the turning; for training, take the leg across under control and pause where the foot is closest to your hand.
What if my foot cannot reach my hand?
Go as far as you can with both shoulders down and stop there — the hand is a direction, not a requirement. Bending the knee shortens the lever and makes the rotation easier to control while you build up to the straight leg.
In StackUp. Logged as reps per set. Add weight if you use a belt or a dumbbell and StackUp progresses it like any other lift. Get the app.
Core
