Climbing strength is built from three systems: max strength (your force ceiling), capacity (your ability to repeat force), and stability (your control under imperfect conditions). Each adapts differently, responds to different training, and creates specific limitations when underdeveloped. Understanding these systems explains nearly all strength plateaus in climbing.

Finger strength is far more neural than muscular. Recruitment determines how many motor units you can activate, how fast they fire, and how well they synchronise. Maximal efforts are required to unlock high-threshold units — endurance work cannot train this system. A proper warm-up alone can increase your usable finger force by 10–20%.

Strength in climbing is the ability to produce high force with stable mechanics in a specific grip and angle. It depends on recruitment, tendon tension, joint stability, and an efficient force line—not just muscle effort or how “strong” a move feels.

Force, time, and stress distribution determine injury risk in climbing. High force, long duration, or unstable mechanics each increase load on pulleys and tendons—and when two or more combine, injury risk spikes sharply. Structured progression works because it controls these variables.

Hold size changes tendon path, joint angles, and pulley stress. Larger edges keep forces smooth and stable, 10 mm edges increase sensitivity, and 6 mm edges create sharp angles that multiply load and instability. You don’t get strong from small edges—you get strong toward them.

Crimp, open hand, and drag grips change tendon path, joint angles, pulley stress, and load distribution. Open hand is smooth and safe, half crimp balances strength and stability, and full crimp creates the highest mechanical stress due to sharp tendon angles.

Bowstringing happens when the flexor tendon lifts away from the bone, increasing pulley tension and destabilizing the finger. It’s the core mechanical failure behind most pulley injuries and is triggered by PIP collapse, DIP unrolling, small edges, dynamic catches, and fatigue-driven angle drift.

Ligaments, joint capsules, and other passive structures stabilize the finger and limit motion under load. They become overloaded when technique collapses, angles drift, or sessions are chaotic. Stable joint angles, slow progression, and predictable training protect passive tissues and reduce irritation.