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Challenge · 2025

#84: 100 Mountain Climbers (Each Leg = 1 Rep)

This 100-rep mountain climber challenge spikes your heart rate and tests your core stability in a simple but savage movement pattern.

By Editorial Team · · Updated

Female athlete performing mountain climbers on gym mat, strong core tension, knees driving toward chest

Mountain climbers are one of the most deceptively simple bodyweight movements in fitness. Done slow, they’re a core stability drill. Done fast, they’re cardio fire. Either way, they build coordination, rhythm, and endurance all without equipment.

In this RB100 Challenge, the task is clear: complete 100 reps of mountain climbers, counting each leg as one rep. Sounds easy, right? Let’s see how you feel at rep 87.

“If your core can’t control your limbs under speed, it’s not ready for pressure.” — RB100.Fitness

Side view of fast-paced mountain climbers, hands planted, core engaged
Side view of fast-paced mountain climbers, hands planted, core engaged

Challenge Format

  • Reps: 100 total (each leg = 1 rep)
  • Standard: Hands under shoulders
  • Core braced, spine neutral
  • Knee drives toward chest without hip sag or bounce

Suggested Approaches:

  • 4 sets of 25 with 20s rest
  • 2 × 50 for a solid burn
  • For time: 100 reps unbroken, timed sprint
  • EMOM: 25 reps per minute for 4 rounds

Track your time and form breakdown in the RB100 Tracker.

Why It Works

Mountain climbers are a compound bodyweight movement with benefits across:

  • Core stability fights lumbar extension
  • Hip mobility and drive crucial for athletes and runners
  • Shoulder endurance stabilising in a loaded position
  • Cardiovascular conditioning gets your heart rate up fast

You’ll feel it in your abs, shoulders, and lungs a trifecta of training stimulus.

Technique Tips

  • Keep hips level no mountain peaks
  • Drive knees like you mean it, not lazily
  • Maintain strong arm position with soft elbows
  • Land softly with midfoot under torso
  • Breathe rhythmically exhale every second or third rep

Scaling & Progressions

Recovery Notes

You’ll feel the fatigue in:

  • Hip flexors and abs
  • Shoulders and wrists
  • Breathing pattern and pacing

Cool down with light stretching, supine breathing, and some cat-cow mobility to reset spine and core.

Learn More

Overhead angle showing symmetry of limb drive and foot placement
Overhead angle showing symmetry of limb drive and foot placement

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