Iso-Lateral Chest Press
The iso-lateral chest press is a plate-loaded machine press in which each handle moves on its own converging arc, so each arm pushes its own load. It works the chest, the front of the shoulders and the triceps through a deep stretch and a strong squeeze at the top, without the balance demand of a barbell or dumbbells.
Also called: Hammer Strength Chest Press, Single Arm Chest Press Machine, Plate-Loaded Iso-Lateral Press, Converging Chest Press · Equipment: machine · Pattern: push
Step by step
- Load the same plates on each side. Set the seat so the handles line up with your mid-chest when you sit with your back on the pad.
- Sit with your feet flat on the floor or the foot rest. Grip the handles with your wrists straight, knuckles up, and your forearms in line with the handles.
- Pull your shoulder blades back and down into the pad and keep your chest up.
- Press both handles forward until your elbows are straight, letting them travel slightly inwards along the arc.
- Squeeze your chest at the top without letting your shoulders roll forward off the pad.
- Bring the handles back under control until you feel a full stretch across your chest, with your shoulder blades still set.
- Press again from the stretch without bouncing. After the last rep, guide the handles back to their resting position before letting go.
- Shoulder blades pinned to the pad
- Handles in line with the mid-chest
- Squeeze the handles together at the top
- Full stretch, then press
- Both arms at the same speed
In VALDA, these cues are one tap away on the exercise while you train.
What it trains
| Muscle | Role | Evidence |
|---|---|---|
| Pectoralis major: sternocostal (mid) | Prime mover | A |
| Anterior deltoid | Secondary | A |
| Triceps brachii: lateral head | Secondary | A |
| Triceps brachii: medial head | Secondary | B |
| Pectoralis major: clavicular (upper) | Secondary | B |
| Triceps brachii: long head | Secondary | C |
| Serratus anterior | Stabiliser | C |
Evidence grades: A = strong research base · B = good · C = limited · D = coaching consensus.
What goes wrong, and the fix
Seat set too low or too high
Fix: Set the seat so the handles line up with your mid-chest before the first set.
Shoulders rolling forward at the top
Fix: Keep your shoulder blades back on the pad and squeeze the chest, not the shoulders.
Short reps at the bottom
Fix: Let the handles come back until you feel a full chest stretch on every rep.
Bouncing out of the stretch
Fix: Control the return and press smoothly from the stretch.
One arm leading
Fix: Move both handles at the same speed and lock out together.
Wrists bent back
Fix: Grip with knuckles up and keep your wrist straight in line with the forearm.
What the research says
Muscle growth · first choiceRehab & prehab · first choiceGeneral fitness · first choiceEndurance · first choiceStrengthFat loss & conditioning
- Machine or free weight — A meta-analysis and a trial in trained lifters found muscle growth does not differ between machine and free-weight training, while strength gains are specific to the tool you train with.
- Load and effort — Research finds growth is similar across a wide range of loads when sets are hard, and that true failure adds only a trivial-to-small benefit. A guided machine lets many lifters take sets close to failure without a spotter.
- Volume — Research links more weekly sets for a muscle to more growth, with diminishing returns. Around 10 or more hard sets a week has been associated with more growth than fewer than 5.
- Range of motion — A meta-analysis found full range of motion gives equal or greater gains than partial range, although upper-body growth comparisons are limited.
- Rest — In trained lifters, rests of about 3 minutes between sets have produced greater strength and size gains than 1-minute rests.
- One arm at a time — The independent arms allow single-arm sets. There is no direct research comparing single-arm and two-arm machine pressing for growth.
Swap it mid-workout
With VALDA Pro, FLEX offers alternatives like these when you swap an exercise mid-workout.
Log the iso-lateral chest press in VALDA, with these cues one tap away while you train and your history for it in one place.
General information about exercise technique, not medical advice. If you have an injury or a health condition, your healthcare provider is the right person to ask.