TRX Plank
What Is the TRX Plank?
TRX Plank is a compound exercise that primarily targets the core and also engages the shoulders, chest and hip flexors. It is an intermediate-level movement held on straight arms with the palms on the floor while the feet hang in the foot cradles of a suspension trainer, so the body stays in one rigid line from head to heels with nothing solid under the legs.
Suspending the feet turns a stable floor hold into an anti-extension challenge where the abs have to stop the hips from sagging and the straps from swaying. In a study of 43 healthy young men who already trained with suspension straps, holding a straight-arm plank with the insteps in TRX straps raised rectus abdominis activity to about 48% of maximum, against about 27% for the same plank on the floor. Putting the hands in the straps instead of the feet raised it far more, which makes that version a later step up.
The rectus abdominis and obliques do most of the work, the serratus anterior and front of the shoulders hold the straight-arm position, and the rectus femoris helps keep the legs level. Because the hold is on the hands rather than the forearms, the shoulders and wrists carry more of the load than in a standard Plank. The same position is the starting point for TRX Pike, TRX Jack Knife and TRX Mountain Climber, so learning to hold it still is the foundation for those moves.
The TRX Plank suits anyone who wants more from core training than a floor plank offers, and it fits well in the core block of a session or as part of a suspension circuit. Build up to a steady 30 to 60 second floor Plank and a solid top position of the Push-Up first, since the straps punish any loss of tension that the floor would hide.
Muscles Worked
- Rectus Abdominis
- Primary
- External Oblique
- High
- Deltoid
- Medium
- Rectus Femoris
- Medium
- Serratus Anterior
- Medium
- Erector Spinae
- Minimal
- Gluteus Maximus
- Minimal
Instructions
- Adjust the straps so the foot cradles hang at mid-calf height, about 8 to 12 inches off the floor.
- Kneel on all fours facing away from the anchor, with your hands flat on the floor directly under your shoulders and your fingers pointing forward.
- Bend your knees and place one foot, then the other, into the foot cradles so the tops of your feet rest in them and your soles face the ceiling.
- Brace your abs, squeeze your glutes and thighs, then straighten your knees to lift them off the floor into a straight-arm plank.
- Hold your body in one straight line from head to heels, with your arms straight and your legs roughly level with your hips.
- Push the floor away so your chest does not sink between your shoulder blades, and keep your neck neutral with your gaze on the floor just ahead of your hands.
- Breathe steadily and press evenly into both cradles so the straps stay still.
- Hold for the set time, then lower your knees to the floor before taking your feet out of the cradles.
Common Mistakes
Sagging hips
Letting the hips drop toward the floor arches the lower back and shifts the strain from the abs onto the lumbar spine.
Piking the hips
Raising the hips above the line of the body shortens the lever and takes most of the work off the abdominals.
Sinking between the shoulders
Letting the chest drop between the shoulder blades instead of pushing the floor away leaves the shoulders hanging on their joints rather than their muscles.
Hands out of line with the shoulders
Placing the hands well ahead of or behind the shoulders adds strain to the wrists and shoulders and makes the hold harder to control.
Uneven pressure in the straps
Pressing harder into one foot cradle makes the straps swing or saw and tips the hips off level.
Holding the breath
Holding the breath to stay rigid shortens the set and spikes blood pressure, so breathe steadily while keeping the abs braced.
Injuries
TRX Plank is a low risk exercise when performed with proper technique. The hold is short and isometric, so problems come from losing position rather than from the load itself. The most common strain point is the lower back: once the abs fatigue and the hips sag, the lumbar spine takes the strain. The wrists, held in extension under part of your body weight, and the front of the shoulders are the other areas that can get irritated.
Keep the hips level, the ribs down and the glutes tight, and end the set as soon as the hips start to drop. Set the cradles at mid-calf height so the feet stay roughly level with the hips, and keep your knees on the floor while you place your feet in and take them out of the cradles. If your wrists complain, holding on your fists or switching to a forearm hold takes the bend out of the wrist.
If the suspended hold is too hard, go back to a floor Plank and build steady 30 to 60 second holds before returning. Once the TRX Plank feels solid for 60 seconds, progress with TRX Mountain Climber, TRX Jack Knife or TRX Pike rather than simply holding longer.
Stop if you feel pain in the lower back, sharp pain in the wrists or shoulders, or if you can no longer keep the hips level and the straps still.
- Primary Focus
- Core
- Equipment
- Suspension trainer and body weight
- Modality
- Strength
- Difficulty
- Intermediate
Alternative Exercises
Frequently Asked Questions
- Q: Is the TRX Plank done on the hands or the forearms?
This version is held on the hands, with the arms straight and the wrists under the shoulders. A forearm version also exists and is a good option if straight-arm holds bother your wrists.
- Q: Is the TRX Plank harder than a regular plank?
Yes. With the feet hanging in the straps, the legs have no fixed support, so the abs have to work harder to keep the hips level and the straps still.
- Q: How long should I hold a TRX Plank?
Start with 20 to 30 seconds per set and build toward 60 seconds with the hips level the whole time. Past 60 seconds, a harder variation such as TRX Mountain Climber does more for you than a longer hold.
- Q: How high should the foot cradles be?
Set them at mid-calf height, about 8 to 12 inches off the floor, so your legs end up roughly level with your hips. Higher cradles raise the feet above the hips and shift more of your body weight onto the hands and shoulders.