Original investigation
Journal of Human Sport And Exercise
Alejandro Muñoz-López, Paulino Granero-Gil, José Pino-Ortega & Moisés de Hoyo Lora
2017 · Volume 12 · Issue 1 · Pages 156-166
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Abstract
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 objectve procedures regarding synchronization with gold standards such as real distance or timing gates. The objective of this study was to study the validity and reliability of a 5Hz GPS system (WIMU) during 10m and 30m sprints and during team sports specific movements and the reliability during very high speeds (> 30 km/h). The Total Distance (TD) BIAS for Circuit A, 10m sprint and 30m sprint were -2.73 ± 1.64 m (p < 0.001), -0.80 ± 0.58 m (p<0.001) and 0.42 ± 2.50 m (p=0.515) respectively. Average ICC for GPS speed point-to- point were 0.976 ± 0.012 and 0.991+ 0.003 for Circuit B and Motorized Sprints, respectively. The average BIAS compared with each unit mean laps (intra-unit reliability) results for TD, Peak-Speed and Avg-Speed were 0.00 + 1.68, 0.00 + 1.73 and 0.00 + 0.33 for Circuit A, 0.00 + 0.49, 0.00 + 0.53 and 0.00 + 0.77 for 10m sprints and 0.00 + 2.34, 0.00 + 0.76 and 0.00 + 0.74 for 30m sprints, non-significant difference in all cases. In conclusion, despite a lower than recommended sample frequency, the WIMU GPS showed to be valid and reliable for measuring sprints at speed higher than 20 km- h-1, as well as for team sport movements.This might be practical on daily physical demands testing during training sessions.