Where should I lie relative to the landmine?

Lie with the top of your head toward the anchor and your body angled so the bar runs diagonally from the anchor down to your working side. Shuffle your position until the bar end can travel from beside your shoulder to above your chest without dragging toward your head or your feet.

Should the plate touch the floor at the bottom?

A light touch or stopping just above the floor are both fine, since the floor simply marks the end of the range. Do not rest, bounce or drop the plate, because that takes tension off the chest and jars the shoulder.

How heavy should I go?

Lighter than you expect. The anchor carries part of the bar's weight, but the fly works on a long lever with one arm, so start with an empty bar or a small plate and add weight only while the elbow bend stays fixed.

Why does the movement feel easy near the top?

When your arm is out to the side the weight sits far from your shoulder, and as the arm comes up over your chest it lines up above the joint and the demand fades. This is the same pattern as a dumbbell fly, so put your effort into a slow, controlled lowering rather than a long squeeze at the top.

Can this replace a bench fly?

It trains the same arc with a shorter range, because the floor stops the arm before it passes your torso. It is a good choice when your shoulders dislike a deep stretch or no bench is free, and the Dumbbell Fly remains the option for a longer range.

Landmine Lying Single-Arm Chest Fly

What Is the Landmine Lying Single-Arm Chest Fly?

Landmine Lying Single-Arm Chest Fly is an isolation exercise that primarily targets the chest and also engages the front of the shoulder and the biceps. It is an intermediate-level movement in which you lie on the floor with the landmine anchor beyond your head and sweep the end of the bar in a wide arc, from out at your side to above your chest, one arm at a time.

The movement trains the main job of the chest: bringing the upper arm across the body. Because the elbow holds one slight bend the whole way, the shoulder does the work and the triceps stay out of it, which is what separates a fly from a press. The landmine pivot keeps the bar end on a fixed arc, so your hand does not have to balance a free weight in every direction, and the floor stops the upper arm from dropping below the line of your torso. It usually sits after the main pressing work as an accessory or finishing chest movement, and it is a practical fly option in a gym that has a landmine but no free bench or cable station.

The chest does most of the work, the front of the shoulder assists, and the biceps hold the elbow angle. Working one arm at a time lets you focus on each side of the chest and keep a weaker side from hiding behind a stronger one, while the trunk works lightly to keep the off-center load from rolling you toward the bar. Like any free-weight fly, the load is hardest when the arm is out to the side and fades as the arm comes up over the chest, so the controlled lowering and the bottom of the arc are where the set is won.

The exercise suits lifters who want a chest isolation movement with a built-in limit on how far the arm can travel, including those whose shoulders dislike the deep stretch of a bench fly. The setup takes a little trial, because where you lie relative to the anchor decides whether the arc lines up with your shoulder. If the fly pattern is new, learn it first on the Machine Pec Deck Fly or with light weights on the Dumbbell Fly, and build basic pressing strength with the Dumbbell Floor Press.

Muscles Worked

MuscleActivation

Pectoralis Major: Primary
Deltoid: High
Biceps Brachii: Medium
External Oblique: Low
Flexor Carpi Radialis: Low
Serratus Anterior: Low
Brachialis: Minimal
Rectus Abdominis: Minimal

Instructions

Load a plate onto the sleeve end of a barbell set in a landmine and lay the bar end on the floor.
Lie on your back on the floor with the top of your head toward the anchor, so the bar runs diagonally from the anchor down beside your working side.
Bend your knees and set your feet flat on the floor. Rest your other arm on the floor beside your torso.
Grip the end of the sleeve, outside the plate, with your working hand, palm facing the ceiling.
Start with your working arm out to your side at about shoulder level, elbow slightly bent, and the plate resting lightly on the floor.
Press your shoulder blade into the floor and brace your trunk.
Keeping the elbow bend fixed, sweep the bar end up and inward in a wide arc until your arm is vertical and the bar end is over your upper chest.
Pause briefly, then lower along the same arc with the same elbow bend until the plate lightly touches or nearly touches the floor.
Finish your reps, set the bar end down on the floor, and reposition on the other side of the bar to work the other arm.

Common Mistakes

Turning it into a press
Bending the elbow on the way down and straightening it on the way up shifts the work to the triceps and front shoulder, so hold one slight elbow bend through the whole arc.
Locking the elbow straight
A fully straight arm lengthens the lever and loads the elbow and the front of the shoulder instead of the chest.
Dropping the plate onto the floor
Letting the plate crash down at the bottom loses tension and jars the shoulder in its most stretched position, so lower it under control and let it touch lightly.
Lying in the wrong spot
Lying too close to, too far from or too square to the bar puts the arc out of line with your shoulder, so the bar end drags toward your head or feet instead of sweeping over your chest.
Lifting the shoulder off the floor
Letting the working shoulder roll forward and up at the top shifts the effort from the chest to the front of the shoulder.
Using too much weight
A load you cannot lower slowly on a single long lever makes the elbow bend and the shoulder take over.

Injuries

Landmine Lying Single-Arm Chest Fly is a low risk exercise when performed with proper technique. The floor stops your upper arm from dropping below your torso, which keeps the shoulder out of the deep, stretched position where bench flys most often irritate it. The points that still take strain are the front of the shoulder at the bottom of the arc, where the arm is out to the side on a long lever, the elbow and biceps tendon if the arm is locked straight, and the wrist if it bends back under the sleeve.

Keep the load light, hold a soft and constant bend in the elbow, and lower the bar end slowly so the plate meets the floor gently instead of dropping onto it. Keep your shoulder blade pressed into the floor and your wrist straight. At the top of the arc the bar runs above your head and face, so use a weight you can grip firmly and control the whole way, and set the bar end down on the floor beside you before you sit up or switch sides.

To make it easier, use an unloaded bar or a smaller plate, or switch to the Machine Pec Deck Fly, where the machine guides both arms. To progress, slow the lowering phase, pause just above the floor, or add weight in small steps; the Dumbbell Fly on a bench adds range once your shoulders tolerate the deeper stretch.

Stop the set if you feel sharp or pinching pain at the front of the shoulder, pain along the biceps tendon or inside of the elbow, clicking that comes with pain, or numbness or tingling down the arm.

Overview

Primary Focus: Chest
Equipment: Barbell and landmine
Modality: Strength
Difficulty: Intermediate

Alternative Exercises

Frequently Asked Questions

Q: Where should I lie relative to the landmine?: Lie with the top of your head toward the anchor and your body angled so the bar runs diagonally from the anchor down to your working side. Shuffle your position until the bar end can travel from beside your shoulder to above your chest without dragging toward your head or your feet.
Q: Should the plate touch the floor at the bottom?: A light touch or stopping just above the floor are both fine, since the floor simply marks the end of the range. Do not rest, bounce or drop the plate, because that takes tension off the chest and jars the shoulder.
Q: How heavy should I go?: Lighter than you expect. The anchor carries part of the bar's weight, but the fly works on a long lever with one arm, so start with an empty bar or a small plate and add weight only while the elbow bend stays fixed.
Q: Why does the movement feel easy near the top?: When your arm is out to the side the weight sits far from your shoulder, and as the arm comes up over your chest it lines up above the joint and the demand fades. This is the same pattern as a dumbbell fly, so put your effort into a slow, controlled lowering rather than a long squeeze at the top.
Q: Can this replace a bench fly?: It trains the same arc with a shorter range, because the floor stops the arm before it passes your torso. It is a good choice when your shoulders dislike a deep stretch or no bench is free, and the Dumbbell Fly remains the option for a longer range.