Validity & Reliability of a GPS device for quantifying athletes´ sprints and movement demands specific to team sports

The objective of this study was to study the validity and reliability of WIMU during 10m and 30m sprints, during team sports specific movements and the reliability during very high speeds (> 30 km/h).

GPS systems are commonly used to analysis football performance during either trainings or matches. While many studies have investigated the validity and reliability of these devices, there is a lack of objective procedures regarding synchronization with gold standards such as real distance or timing gates. This the first study that uses a high-speed video camera synchronized via software with a GPS device and timing gates to determine the sprint start point and sprint split. In conclusion, WIMU showed to be valid and reliable for measuring sprints at speed higher than 20 km/h as well as team sport movements

Infographics by José María Oliva

Reliability & Validity of WIMU for measuring velocity during resistance exercises

First study to test the reliability and validity of WIMU enclosed to a Smith’s machine bar in order to measure velocity in back squat. This study had two main goals. The first was to determine the reliability of the WIMU for mean velocity measurements during resistance exercises at 40% and 80% 1 repetition maximum (maximum weight you can lift with maximum effort in a single repetition). The second was to compare the results for the WIMU to a linear encoder (gold standard) for mean velocity measurements when clipped to the bar during back squat exercises using the Smith machine.

23 trained men aged 22.3 ± 3.2 years participated in this study. At maximum velocity in the concentric phase, they performed 10 repetitions with 40% 1 repetition maximum and eight repetitions with 80% 1 repetition maximum while using the WIMU and T-Force linear encoder simultaneously to record data.

In conclusion, the findings of this study suggest that WIMU is a reliable and valid tool for the assessment of mean velocity during the back squat exercise using the Smith machine. These findings could help coaches and sport researchers evaluate athletes performing resistance exercises similar to squats with a reliable, valid and portable tool.

Infographics by José María Oliva