Why Climbing Demands Unique Strength

Rock climbing is a sport that demands unique control of the human body in vertical and overhanging environments. Every movement requires precision between strength, endurance, and stability. Unlike many traditional sports that emphasize concentric (shortening) muscle actions, climbing relies heavily on eccentric and isometric strength. Climbers must not only generate upward force but also absorb, control, and sustain muscular tension against gravity.

Key Performance Characteristics for Climbers

What separates good climbers from the very best often comes down to the forearm flexors:

• Hang time
• Force output
• Rate of force development (RFD)
• Oxidative capacity

Rock climbing requires constant transition between eccentric and isometric muscle actions. For instance, a climber catching a dynamic move must eccentrically decelerate their body weight, then isometrically stabilize before initiating the next movement. This cycle repeats continuously during every ascent, particularly on steep or dynamic routes. This eccentric–isometric synergy is also evident in tendon loading patterns. Tendons stretch eccentrically to store elastic energy, then stabilize isometrically before transmitting force. Training both components enhances energy efficiency, movement precision, and injury resilience.  

Eccentric Strength in Climbing

Eccentric contractions occur when muscles lengthen under tension, typically during the lowering or braking phase of movement. In climbing, eccentric strength is critical for controlling body position and absorbing impact when transitioning between holds, descending from a move, or catching a dynamic lunge. For example, downclimbing and lowering during descents requires controlled eccentric activation of the elbow and knee extensors, as well as the core, to handle gravitational load or when performing a large reach, eccentric control of the shoulder extensors, biceps, and finger flexors prevent overextension and stabilizes contact with the new hold.

Why Flywheel Training Helps Climbers

Into this performance space I would implement flywheel resistance training as it offers unique advantages over traditional weight training due to its ability to provide constant, accommodating resistance through both the concentric and eccentric phases of movement. The eccentric stimulus promotes greater strength development, particularly by recruiting high-threshold motor units and enhancing force production capacity. This eccentric overload improves neuromuscular control, allowing athletes to coordinate rapid contractions and stabilizations more effectively during dynamic or decelerative actions. Additionally, the repeated eccentric tension facilitates tendon adaptation, increasing stiffness and resilience, which enhances force transfer efficiency while reducing the risk of strain or overuse injuries.  

Isometric Strength in Climbing

Isometric strength is the ability to generate force without joint movement, holding a static position under tension. In climbing, this is arguably the dominant contraction type across all disciplines, as climbers frequently sustain body positions on the wall for extended periods.

Examples:

• Grip endurance when a hold requires constant isometric contraction of the finger flexors for several seconds or minutes.
• Core stability when climbers must isometrically brace the trunk and hip stabilizers to maintain tension between the hands and feet, especially on overhanging routes.

Examples of training drills

Developing eccentric strength specific to climbing:

• Eccentric hangs: Lowering from small edges over 3–5 seconds to build controlled finger extensor loading.

• Eccentric pull-ups: Slow descent phases to strengthen shoulder and elbow stabilizers.

• Flywheel resistance training or weighted negatives for climbing-specific pulling patterns. The combination of exercises such as rows, presses, pull-downs with velocity have been shown to enhance RFD.

• Eccentric training: Overload or flywheel methods exploit the high-force capacity of eccentric contractions to enhance muscle size, control, and injury resilience.

• Accentuated Eccentric Training: involves loads greater during the eccentric phase compared to then concentric while preserving the SSC.

Developing isometric strength requires specificity in joint angles and contraction durations:

• Fingerboard hangs: Static holds at various edge depths and durations.

• Lock-off drills: Pausing at multiple positions during pull-ups to reinforce joint-specific isometric control.

• Core tension exercises: Front levers, planks, and dead-hang to toe-up positions to mimic climbing postures.

• Isometric shoulder exercises: Scapular retraction holds and isometric external rotations for shoulder integrity.

Exerfly Motorized Eccentric Technology

• Exerfly’s motorized flywheel technology: This technology enhances eccentric overload up to 80%, adjusting in real time based on the concentric force. For example, if set to a 20% boost, the eccentric phase gains 20% more energy than during the concentric phase.

Tendon Health + Injury Resilience

Eccentric and isometric strength are not only performance drivers but also protective mechanisms.

For example

• Eccentric control reduces peak impact forces during dynamic catches or slips, lowering strain on the finger flexor and shoulder tendons.
• Isometric endurance stabilizes joints under sustained load, preventing microtrauma accumulation and training both modalities develop tendon resilience, improving collagen alignment and stiffness, critical for long-term health in climbers who perform thousands of submaximal contractions per session.

Summary

In summary eccentric and isometric strength form the physiological foundation of rock-climbing performance. While eccentric strength allows climbers to control momentum, absorb impact, and move fluidly between holds, isometric strength sustains positions, maintains body tension, and supports technical precision.

The most effective climbers integrate both—absorbing forces efficiently and sustaining postural stability under fatigue. By optimizing these two contraction types, climbers can improve performance, movement control, and reduce the risk of injury.

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References

Giles, L.V, Rhodes, E.C. & Taunton, J.E. (2006) The physiology of rock climbing. Sports Medicine 36(6): 529-545.

Martinez-Hernandez, D. (2023) Flywheel Eccentric Training: How to Effectively Generate Eccentric Overload. Strength & Conditioning Journal. 1-17.

Stien, N., Riiser, A., Shaw, M.P., Saeterbakken, A.H. & Andersen, V. (2023) Effects of climbing-and resistance-training on climbing-specific performance: a systematic review and meta-analysis. Biology of Sport 40(1): 179-191.

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