TRX Mountain Climber
What Is the TRX Mountain Climber?
TRX Mountain Climber is a compound exercise that primarily targets the core and also engages the hip flexors, shoulders and chest. It is an intermediate-level movement performed in a straight-arm plank with the hands on the floor and the feet in the foot cradles of a suspension trainer, driving one knee toward the chest at a time while the other leg stays extended.
On the floor, the back foot can push against the ground on every switch. With the feet hanging in the straps, the extended leg has nothing solid behind it, so the abs and obliques have to keep the hips level, stop them from twisting toward the moving leg and keep the straps from swinging. Each knee drive briefly turns a two-legged plank into a one-legged one, which makes this a natural step up from the TRX Plank and a harder, slower relative of the floor Mountain Climber.
The rectus abdominis does most of the work, with the lower abs and the hip flexors pulling each knee in and the obliques resisting rotation. The serratus anterior, front of the shoulders and chest hold the straight-arm position throughout. Slow drives with a short pause as the knee comes in keep the emphasis on the core, while a quicker pace turns the move into conditioning work. Threading one foot through both cradles and driving the free knee is a harder single-leg version.
The TRX Mountain Climber suits anyone who can already hold a steady suspended plank and wants a dynamic core exercise, and it fits well in the core block of a session or in a suspension circuit. Build up to a solid 30 to 60 second TRX Plank and controlled floor Mountain Climbers with level hips first, since every switch in the straps exposes any loss of tension.
Muscles Worked
- Rectus Abdominis
- Primary
- External Oblique
- High
- Rectus Femoris
- High
- Deltoid
- Medium
- Serratus Anterior
- Medium
- Tensor Fasciae Latae
- Medium
- 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.
- 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 and straighten your knees to lift into a straight-arm plank, with your body in one line from head to heels and your legs roughly level with your hips.
- Keeping your hips level, draw your right knee forward under your body toward your chest, letting the strap travel with your foot.
- Press your left foot steadily into its cradle so the extended leg stays still and your hips do not twist.
- Extend your right leg back to the plank, then drive your left knee in the same way.
- Keep alternating at a controlled pace, with your arms straight, your shoulders over your wrists and your breathing steady.
- After the final rep, return to the plank, lower your knees to the floor and take your feet out of the cradles.
Common Mistakes
Sagging hips
Letting the hips drop toward the floor arches the lower back and moves the strain from the abs onto the lumbar spine.
Bouncing the hips up
Lifting the hips high with each knee drive shortens the lever and takes much of the work off the abdominals.
Rushing the drives
Moving faster than you can control makes the straps swing and the feet bounce in the cradles, so the core stops doing the stabilizing work.
Twisting toward the moving leg
Letting the hips rotate as each knee comes in means the obliques are no longer resisting the rotation the single-leg support creates.
Cutting the knee drive short
Stopping the knee well short of the hips turns the rep into a leg shuffle and leaves the abs and hip flexors underworked.
Shoulders sinking
Letting the chest drop between the shoulder blades or the hands drift ahead of the shoulders adds strain to the shoulders and wrists.
Injuries
TRX Mountain Climber is a low risk exercise when performed with proper technique. There is no external load, so problems come from losing position as the abs tire. The lower back is the main strain point: when the hips sag, or the pelvis tips forward as a knee drives in, the lumbar spine takes the load instead of the abs. The wrists, held in extension under part of your body weight, and the front of the shoulders are the other common complaints.
Keep your hands under your shoulders, push the floor away and keep the ribs down so the body stays in one line between knee drives. Move only as fast as you can keep the hips level and the straps still, and end the set when the hips start to drop or twist. Set the cradles at mid-calf height and seat your feet fully in them so they cannot slide out mid-set, and keep your knees on the floor while you get in and out. If your wrists complain, holding the plank on your fists takes the bend out of the wrist.
If the suspended version is too hard, go back to the TRX Plank or the floor Mountain Climber, or slow the drives down and pause in the plank between them. Once alternating drives feel controlled, progress to the TRX Jack Knife, which pulls both knees in together, and then the TRX Pike.
Stop if you feel pain in the lower back, sharp pain in the wrists or shoulders, a pinch at the front of the hip as the knee comes in, or if you can no longer keep the hips level and the straps steady.
- Primary Focus
- Core
- Equipment
- Suspension trainer and body weight
- Modality
- Strength
- Difficulty
- Intermediate
Alternative Exercises
Frequently Asked Questions
- Q: Is the TRX Mountain Climber harder than a regular mountain climber?
Yes. With the feet in the straps, the extended leg cannot push against the floor, so the abs and obliques have to keep the hips level and the straps still on every switch. Most people need to move more slowly than they would on the floor.
- Q: Should TRX Mountain Climbers be done fast or slow?
Start slow, with a brief pause as each knee comes in, and speed up only as far as you can keep the hips level and the straps steady. Slower reps keep the work on the core, while faster ones turn the move into conditioning.
- Q: How is the TRX Mountain Climber different from the TRX Jack Knife?
The TRX Mountain Climber drives one knee in at a time while the other leg holds the plank, so the core also has to resist twisting. The TRX Jack Knife pulls both knees in together and is the usual next step.
- Q: Why do my feet slip out of the foot cradles?
The cradles are usually hanging too low or the feet are only partly in them. Shorten the straps to mid-calf height, push your feet in until the tops of your feet sit fully in the cradles, and keep pressing down into them as you move.
- Q: How should I count reps?
Count each knee drive, so 20 reps is 10 per leg, and keep the same method every session so your log stays comparable. Sets of 10 to 20 drives per leg are a sensible place to start.