Mountain Climbers — CrossFit Technique Guide
Mountain climbers are a dynamic core and cardio movement performed in a high plank — you drive alternating knees toward the chest as fast as possible while maintaining a rigid plank in the upper body. In CrossFit, they are counted either as individual reps (each knee drive = 1) or in pairs (left + right = 1) — always confirm the standard before a WOD. Mountain climbers train hip flexor strength, anti-rotation core stability, and cardiovascular capacity simultaneously. They require no equipment and a minimal footprint, making them a staple in no-equipment and travel programming.
Muscles Worked
Equipment
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How to Do the Mountain Climbers
Set up in a high plank: hands directly under shoulders, body forming a straight line from head to heel.
Engage the core — prevent hips from rising or sagging throughout the movement.
Drive one knee toward the chest as quickly as possible.
Return that foot to start while simultaneously driving the opposite knee forward.
Alternate as fast as mechanics allow, maintaining a stable plank with the upper body.
Common Mistakes
Hips piking upward — the most common fault. Keep hips level with the shoulders.
Not driving the knee fully toward the chest — a half rep reduces the hip flexor demand significantly.
Arms bending — lock elbows and let the shoulders support bodyweight.
Loud, bouncing feet — quiet feet usually indicate better mechanics and more core engagement.
Coaching Tips
Count cadence rather than going "as fast as possible" — consistent pace over 40 reps beats sprint-and-collapse.
Exhale with each knee drive — this maintains intra-abdominal pressure and protects the lower back.
Elevating hands on a box reduces the shoulder and core demand — useful for warm-ups or high-volume sets.
Scaling Options
Easier / Beginner
Slow mountain climbers (controlled knee drive, 2 sec per rep), or hands elevated on a box.
Harder / Advanced
Cross-body mountain climbers (knee to opposite elbow), or sliders under the feet.
Frequently Asked Questions
How are mountain climbers counted in CrossFit?
Most coaches count each knee drive as one rep (20 mountain climbers = 10 each side). Some count left + right as one rep. Always clarify the standard before starting the WOD — it makes a big difference on total volume.
Related Exercises
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