Does the operating temperature of accelerometers affect data measurement during static and dynamic conditions in sports? A randomized-control trial

Abstract

This study aimed to analyse the effect of two operating temperatures (optimal vs environmental) on IMU internal temperature and accelerometry-based data in two conditions of measurement: (a) static, no movement; and (b) dynamic, a U’16 game-based training soccer session with 14 players. Each session took a 60-min duration and followed an ecological design (no intervention in environmental conditions). Fifty-six WIMU PRO^TM inertial devices were randomly grouped in four conditions (two operating temperatures × two measurement conditions, 14 devices in each group) and recorded IMUs’ internal temperature, resultant acceleration vector and PlayerLoad (PL_RT). Devices were placed in the manufacturer’s docking station at the static condition and in a specific harness at the interscapular level at the dynamic condition. Repeated measures t-tests were employed for between-group comparisons at 1-min average sections throughout the register. Between-group differences were found in the static and dynamic conditions in IMUs internal temperature (static: 0–31 min; dynamic: 0–20 min) and resultant acceleration vector (static: 0–29 min; dynamic: 0–19 min). Instead, no differences were found in PL_RT dynamics and accumulated PL_RT although values in the environmental group were overestimated. In conclusion, WIMU PRO^TM devices must achieve the optimal operating temperature (38–39°) to avoid measurement error, regardless of the application (short or long sessions).