Relationship between Internal and External Estimates of Training Load Using Wearable Inertial Sensors.

Document Type


Publication Date



PURPOSE: The purpose of the study was to examine the relationship between an external estimate of training load obtained from a wearable accelerometer device and perceived training load in women’s volleyball. METHODS: Participants of this study were thirteen NCAA Division I women’s volleyball players (Age: 20.3±1.2 y, height: 174.9±7.9cm, body mass: 68.1±12.7 kg). A wearable accelerometer device (Catapult Sports, MiniMaxX S4) was used to estimate external training load during volleyball practice sessions. In addition, following each session a rating of perceived exertion was obtained from each player using a 0-10 scale. Based on previously established methods, ratings of perceived exertion were then multiplied by the duration of practice in minutes to provide an estimate of internal training load. A Pearson product-moment zero order correlation coefficient was used to assess the relationship between external and internal training load estimates for each individual over eight practices. RESULTS: On average a positive relationship (r = 0.75±0.15) was found between training load estimates. Individual r values ranged from 0.39 to 0.92, with eight of the thirteen achieving statistical significance (p<0.05). CONCLUSIONS: Based on the relationships found between internal and external estimates of training load, both methods may be considered as an option for quantifying on-court training loads in NCAA women’s volleyball. However, the degree to which these estimates relate may vary by individual.


Jacksonville, FL

This document is currently not available here.