Wearable and Non-Invasive Sensors for Rock Climbing Applications: Science-Based Training and Performance Optimization

Abstract

Rock climbing has evolved from a method for alpine mountaineering into a popular recreational activity and competitive sport. Advances in safety equipment and the rapid growth of indoor climbing facilities has enabled climbers to focus on the physical and technical movements needed to elevate performance. Through improved training methods, climbers can now achieve ascents of extreme difficulty. A critical aspect to further improve performance is the ability to continuously measure body movement and physiologic responses while ascending the climbing wall. However, traditional measurement devices (e.g., dynamometer) limit data collection during climbing. Advances in wearable and non-invasive sensor technologies have enabled new applications for climbing. This paper presents an overview and critical analysis of the scientific literature on sensors used during climbing. We focus on the several highlighted sensors with the ability to provide continuous measurements during climbing. These selected sensors consist of five main types (body movement, respiration, heart activity, eye gazing, skeletal muscle characterization) that demonstrate their capabilities and potential climbing applications. This review will facilitate the selection of these types of sensors in support of climbing training and strategies.

Keywords: biomonitoring; bouldering; breathing sensors; cardiac sensors; external and embedded sensors; non-invasive sensors; outdoor climbing; physical sensors; rock climbing; speed climbing; sport climbing; wearable sensors.

Figure 1

Types of indoor (a–d) and outdoor (e–h) rock climbing. The four types of indoor climbing include bouldering (a), top rope (b), sport lead (c), and speed climbing (d). The four types of outdoor climbing include bouldering (e), top rope (f), sport lead (g), and traditional (trad) lead climbing (h). Indoor bouldering (a) shows a blue padded floor below the climber. Indoor top rope climbing (b) shows the rope path that goes above the climber to a top anchor and then towards the floor to a belayer below. Indoor lead climbing (c) shows anchors (red circles) along the climbing route. Indoor speed climbing (d) shows the rope path that goes above the climber to a top anchor. Outdoor bouldering (e) shows several ground pads below the climber. Outdoor top rope climbing (f) shows the rope path that goes above the climber to a top anchor and then towards the ground to a belayer below. Outdoor lead climbing (g) shows anchors (red circles) along a climber’s route. Outdoor trad lead climbing (h) shows a removable anchor (red circle) inserted in a large crack in the rock near a climber.

Figure 2

Sensors used during climbing. The five types of sensors are respiration, movement, eye gazing, heart, and skeletal muscles, which consist of wearable sensors (blue boxes), embedded force sensors and external scene cameras (tan boxes).

Figure 3

Examples of sensors used during climbing. Movement sensors: (a) Hexoskin biometric shirt with accelerometer inside hip pocket (green), (b) MotionPod IMU attached to various body segments (red), (c) Pedar-X force sensors within shoe insoles (red), (d) motion capture system with external camera, reflective body markers (red). Respiration sensors: (a) Hexoskin biometric shirt with thoracic and abdominal chest band displacement sensors (blue), (e) METAMAX 3B with face mask and chest-mounted data collection system. Eye gazing sensor: (f) Tobii Pro Glasses with eye tracking cameras (red) and scene camera (green). Heart sensors: (a) Hexoskin biometric shirt with three flexible ECG sensors (red), (g) Polar monitor with chest band ECG sensors (red). Skeletal muscle sensors on forearm (red): (h) EMG electrodes, (i) PortaMon with NIRS sensor.

Figure 4

Examples of raw data collected during lead climbing from three types of wearable sensors (movement, heart, respiration). Data are shown across three consecutive periods (a–c) with different climbing activities (Breen 2022, [14]). First period (a) corresponds to climber interacting with climbing surface (e.g., hold change, rope clipping) that shows increasing heart rate (HR), breathing rate (BR), minute ventilation (V_E) and many large peak-to-valley changes in hip acceleration (HA). Each HA peak often corresponds to a hold change. Second period (b) corresponds to immobility (e.g., resting, route finding) and stationarity (e.g., chalking, limb shaking) that shows decreasing HR, BR, V_E, and mostly small peak-to-valley changes in HA. Third period (c) corresponds to climber interacting with climbing surface (e.g., hold change, rope clipping) that shows characteristics similar to period (a).

Figure 5

Examples of data from two types of sensors: eye gazing sensors (a–c), and NIRS skeletal muscle sensor (d). Eye gazing data during indoor lead climbing show the climber’s gaze location (green dot) overlaid on a sequence of three images from the scene video camera of eye tracking glasses. The first and second images (a,b) show a climber maintaining their eye gaze on the same hand hold. The third image (c) shows the climber shifting their gaze to the next hand hold. The NIRS sensor data (d) show moderate (60–70%), low (35%), and high (80–85%) muscle oxygen saturation during moderate-intensity (Period A), high-intensity (Period B), and low-intensity (Period C) muscle exertion, respectively.