Author Identifier
Date of Award
2026
Keywords
rugby, GPS, monitoring, biomechanics, exercise physiology
Document Type
Thesis - ECU Access Only
Publisher
Edith Cowan University
Degree Name
Master of Medical and Health Science by Research
School
School of Medical and Health Sciences
First Supervisor
Oliver Barley
Second Supervisor
Shayne Vial
Abstract
Effective athlete monitoring in elite rugby union requires balancing methodological rigour with practical feasibility across a demanding competitive season. While wearable technologies such as global positioning systems (GPS) are routinely embedded within high-performance programs, sub-maximal fitness tests (SMFTs) have been proposed as structured, low-burden tools for monitoring athlete responses without adding fatigue. However, uncertainty remains regarding i) whether acceleration signals from GPS-embedded inertial sensors preserve waveform characteristics relative to sacral-mounted inertial measurement units (IMUs), and ii) which variables collected during a continuous-fixed intensity SMFT are sensitive to seasonal changes in training load. To address these gaps, two studies were conducted within an elite male rugby union academy across one competitive season.
Study one evaluated waveform-level similarity and between-session reliability of resultant acceleration from thoracic-mounted GPS-embedded IMUs relative to sacral-mounted IMUs during steady-state overground running. Ten athletes completed two 4-minute SMFTs at ~70% maximal aerobic speed. Cosine similarity, mean absolute error (MAE), root mean squared error (RMSE), and Bland-Altman analyses quantified agreement and reliability. Thoracic GPS embedded acceleration showed strong similarity to sacral IMU signals (0.90±0.02 and 0.89±0.02), trivial error (MAE 0.019; RMSE 0.022), negligible mean bias (-0.004), and narrow limits of agreement (-0.048 to 0.040). These findings support the applied use of thoracic GPS embedded IMUs for measuring acceleration during steady-state running.
Study two assessed the sensitivity of physiological, locomotor, perceptual, and exploratory non-linear (sample entropy) variables collected during a weekly SMFT to changes in on-field training and match load, while accounting for gym-based volume. Twenty-seven athletes were monitored across 13 weeks. Linear mixed-effects models examined within-athlete associations. GPS-derived locomotor variables were significantly associated with on-field load (R2marginal 0.04-0.30). Sessional rating of perceived exertion (sRPE) showed the strongest relationship (R2marginal 0.98) and remained meaningfully associated when collected post-SMFT (R2marginal 0.12). Exercise heart rate, POMS-16 fatigue, and sample entropy showed the weakest associations under fixed-intensity conditions.
Overall, this thesis demonstrates that effective monitoring depends on both measurement validity and variable responsiveness. Thoracic GPS-embedded IMUs preserved acceleration waveform structure, supporting their use in biomechanical analysis. Within fixed intensity SMFTs, perceptual measures, particularly sRPE, were most sensitive to week-to-week load changes, whereas physiological measures and sample entropy showed limited responsiveness. These findings support a variable-focused monitoring approach that prioritises measures with clear load sensitivity within the practical constraints of elite rugby union and similar team-sport environments.
Access Note
Access to this thesis is embargoed until 2nd July 2031
Recommended Citation
Wong, B. (2026). Applied approaches to monitoring athlete responses using sub-maximal testing in elite rugby union. Edith Cowan University. https://doi.org/10.25958/b0k1-jw89