Cross-Body Mountain Climber
What Is the Cross-Body Mountain Climber?
Cross-Body Mountain Climber is a compound exercise that primarily targets the core and also engages the hip flexors, shoulders and chest. It is a beginner-level movement that only needs body weight and enough floor space to hold a plank.
It keeps the high plank and alternating knee drive of the Mountain Climber, but each knee travels diagonally under the body toward the opposite elbow instead of straight toward the chest. As one leg crosses under, the hips and trunk are pulled toward rotation, so the obliques have to work harder to keep the hips level while the abdominals and hip flexors draw the knee in. The arms stay straight and the shoulders hold the body up the whole time. Coaches often use it as the next step after the standard version, and it fits HIIT circuits, core finishers and warm-ups, usually for timed intervals.
Tempo changes what the exercise trains. Slow, deliberate reps with a brief pause as the knee nears the elbow put the emphasis on core control and the crossing pattern, while a quicker rhythm raises the heart rate and turns it into conditioning. It shares the elbow-to-opposite-knee idea of the Cross-Body Crunch, but done in a plank, so the shoulders and trunk also have to support the body against gravity.
It suits anyone who can hold a solid Plank on straight arms and already does regular mountain climbers with level hips. If the hips sway or sag, build up with longer plank holds and slow standard mountain climbers, or place the hands on a sturdy bench. People who cannot load their wrists can train a similar knee drive upright with the Standing Mountain Climber.
Muscles Worked
- External Oblique
- Primary
- Rectus Abdominis
- Primary
- Deltoid
- High
- Rectus Femoris
- High
- Pectoralis Major
- Medium
- Serratus Anterior
- Medium
Instructions
- Start in a high plank with your hands under your shoulders, arms straight and fingers spread.
- Set your feet close together on the balls of your feet and hold a straight line from head to heels.
- Brace your abs and keep your gaze on the floor just ahead of your hands.
- Drive your right knee forward and across under your body toward your left elbow, keeping the right foot off the floor.
- Keep your shoulders over your hands and your hips close to shoulder height, letting them turn only slightly as the knee crosses.
- Return your right foot to the plank, landing on the ball of the foot.
- Drive your left knee across toward your right elbow, then return it to the plank.
- Keep alternating sides at a steady rhythm, exhaling as each knee crosses.
- Continue for the set time, slowing down if your hips start to sag, pike or swing.
Common Mistakes
Swinging the hips
Rolling the hips toward the floor or swaying them side to side on every cross turns the oblique work into momentum and twists the lower back.
Short cross
Driving the knee straight forward or stopping it at the middle of the body turns the exercise back into a regular mountain climber.
Sagging hips
Letting the hips drop below the line of the shoulders puts the load on the lower back instead of the abdominals.
Piking
Lifting the hips into an inverted V makes the knee drive easier but takes most of the core work out of the plank.
Shoulders behind the hands
Letting the shoulders drift back behind the wrists as fatigue builds shortens the knee drive and makes the plank harder to control.
Rushing
Going faster than you can control leads to bouncing on the toes and loose reps where the knee no longer crosses the body.
Injuries
Cross-Body Mountain Climber is a low risk exercise when performed with proper technique. Most of the load sits on the wrists and shoulders, which hold the body up in a straight-arm plank for the whole set. The lower back is the other weak point: if the core tires and the hips sag, or the hips roll toward the floor each time a knee crosses, the lumbar spine ends up resisting the twist instead of the obliques.
Keep the wrists stacked under the shoulders, spread the fingers and press the floor away. Let the knee do the crossing while the hips stay close to shoulder height and turn only slightly, and slow down as soon as the hips start swinging from side to side. Fists or push-up handles keep the wrists neutral for people who find a flat hand uncomfortable.
To make it easier, place the hands on a sturdy bench or box, slow the tempo, or go back to the standard Mountain Climber until the hips stay level. To make it harder, hold each knee near the opposite elbow for a moment, speed up while keeping the hips level, or progress to the TRX Mountain Climber.
Stop if you feel sharp pain in the wrists, shoulders or lower back. A pinch at the front of the hip as the knee crosses usually means it is being forced too far across, so shorten the cross, and stop if the pain stays. People with wrist or shoulder injuries can use the Standing Mountain Climber instead.
- Equipment
- Body weight
- Modality
- Cardio
- Difficulty
- Beginner
Alternative Exercises
Other Names for the Cross-Body Mountain Climber
The Cross-Body Mountain Climber is also known as:
- Oblique Mountain Climber
- Mountain Climber Crossover
Frequently Asked Questions
- Q: How is a cross-body mountain climber different from a regular mountain climber?
In a regular Mountain Climber each knee drives straight toward the chest. Here it travels diagonally under the body toward the opposite elbow, so the trunk has to resist being pulled into rotation, which makes it a harder core exercise at the same pace.
- Q: What is the difference between a cross-body and a Spiderman mountain climber?
A Spiderman mountain climber brings the knee outside the arm toward the elbow on the same side, which asks more of hip mobility. The cross-body version drives the knee under the body toward the opposite elbow, so it is about controlling rotation rather than opening the hip.
- Q: Does my knee have to touch my elbow?
No. Aim the knee toward the opposite elbow and get it clearly past the middle of your body, but stop where your hips can stay level. Forcing the knee all the way to the elbow usually makes the hips twist or pike.
- Q: Should I do cross-body mountain climbers fast or slow?
Slow, controlled reps build core control and are the best way to learn the crossing pattern. Once the hips stay level, a faster pace for intervals of 20 to 40 seconds turns them into conditioning.
- Q: What if cross-body mountain climbers hurt my wrists?
Try making fists or using push-up handles to keep the wrists straight, or put your hands on a sturdy bench to take some weight off them. If it still hurts, the Standing Mountain Climber trains a similar knee drive without loading the hands.