Wearable Sensors in Rock Climbing: From Data to Practical Performance Metrics

Wearable Sensors in Rock Climbing: From Data to Practical Performance Metrics

The integration of wearable and non-invasive sensor technologies has sparked new opportunities in how we understand and train rock climbers. In many ways, this parallels broader shifts in sport science, where objective, continuous data collection has replaced anecdotal or purely observational practices. The review by Breen et al. (2023) provides a comprehensive overview of how sensors can quantify biomechanical, physiological, and even cognitive metrics during actual climbing, rather than in a lab or static environment.

One of the key shifts this paper highlights is moving beyond traditional dynamometry — which is limited to off-wall, single-plane force measurements — toward dynamic, climbing-specific measurements. The five major sensor categories outlined (body movement, respiration, heart activity, eye gazing, skeletal muscle oxygenation) each offer distinct physiological and performance-relevant metrics, supporting a more integrated view of climbing performance.

Body Movement Sensors

Body movement sensors, including inertial measurement units (IMUs), pressure-sensing insoles, and motion capture systems, offer detailed information on climbing fluency. For example, quantifying the geometric entropy of center-of-mass movement, also known as the “jerk coefficient,” is one way to assess movement efficiency. These metrics can reflect the athlete’s skill in conserving energy and controlling posture on overhanging or vertical terrain.

This has practical relevance: reducing unnecessary acceleration and deceleration during climbing translates directly to less peripheral fatigue in the forearm and improved local oxygen availability. Similarly, embedded force sensors within climbing holds can measure force distribution between hands and feet, which is valuable for understanding how athletes offload the finger flexors to larger muscle groups — a foundational principle of climbing economy.

Respiratory and Heart Activity Sensors

Respiratory sensors, whether through direct gas analysis (like a metabolic cart) or indirect methods such as respiratory inductive plethysmography (RIP), allow for quantification of breathing rate, tidal volume, and minute ventilation in real time. These parameters are tied closely to perceived exertion and fatigue.

What’s useful about this approach is its ability to differentiate systemic from local oxygen demands. Systemic oxygen uptake, tracked by minute ventilation, reflects the aerobic contribution of larger muscle groups (e.g., legs, trunk), while local desaturation measured by NIRS gives a window into the status of the finger flexors. Because local ischemia from prolonged isometric contractions is one of the limiting factors in climbing, combining these metrics provides a clearer picture of where fatigue is actually occurring.

Heart rate monitoring — usually via ECG integrated in compression shirts — adds another dimension. Although heart rate is influenced by fear of falling or wall inclination and may not directly measure finger flexor fatigue, it still offers a window into psychophysiological stress and readiness to perform, especially if paired with heart rate variability.

Eye Gazing and Visual Strategies

Visual–motor skills are increasingly recognized as a hallmark of high-level climbing. Eye-tracking sensors embedded in glasses provide data on gaze patterns during route preview and ascent. Skilled climbers tend to use proactive gaze strategies, identifying critical holds and mentally rehearsing movement sequences, whereas less experienced climbers exhibit more fragmented scanning behavior.

Quantifying gaze complexity — or even entropy of gaze patterns — might help coaches teach more efficient visual search behavior, which supports smoother, more confident movement.

Skeletal Muscle Sensors

Surface electromyography (EMG) and near-infrared spectroscopy (NIRS) provide direct measures of forearm muscle activation and oxygenation. Unlike systemic tests of endurance (like cycling or treadmill VO2max), these sensors zero in on local fatigue, which is far more relevant to climbing performance.

Repeated isometric contraction of the finger flexors creates a pattern of localized hypoxia and rapid fatigue. NIRS measures, such as the muscle oxygen breakpoint or recovery kinetics, are potential metrics to monitor how well an athlete’s forearms tolerate repeated gripping efforts, and how quickly they recover between efforts — two clear indicators of climbing-specific endurance.

Practical Implications

From a practical strength and conditioning perspective, the combination of these wearable sensors allows us to:

  • Measure movement fluency (jerk coefficient, geometric entropy)

  • Quantify local versus systemic oxygen demands

  • Monitor stress and recovery (heart rate and HRV)

  • Assess visual-motor planning (eye tracking)

  • Profile local muscle fatigue and oxygenation in the finger flexors

These measurements can help guide programming decisions — for example, whether to emphasize movement drills to improve fluency, finger flexor capacity work to improve local oxygen delivery, or psychological interventions to address fear-based stress responses.

While many of these sensors remain somewhat impractical for daily training, their use in testing scenarios or research settings offers a promising path to more tailored, data-driven interventions for climbers.

Citation:
Breen M, Reed T, Nishitani Y, Jones M, Breen HM, Breen MS. Wearable and Non-Invasive Sensors for Rock Climbing Applications: Science-Based Training and Performance Optimization. Sensors 2023; 23(11):5080. doi:10.3390/s23115080

Tyler Nelson