The Interunit Reliability of Global Navigation Satellite Systems Apex (STATSports) Metrics During a Standardized Intermittent Running Activity

Abstract

Beato, M, Wren, C, and de Keijzer, KL. The interunit reliability of global navigation satellite systems Apex (STATSports) metrics during a standardized intermittent running activity. J Strength Cond Res XX(X): 000–000, 2023—This study aimed to evaluate the interunit reliability of global navigation satellite systems (GNSS) STATSports Apex metrics and to assess which metrics can be used by practitioners for the monitoring of short-distance intermittent running activities. Fifty-four male soccer players were enrolled (age = 20.7 ± 1.9 years, body mass = 73.2 ± 9.5 kg, and height = 1.76 ± 0.07 m) in this observational study. 10-Hz GNSS Apex (STATSports, Northern Ireland, Newry) units recorded total distance, high speed running (HSR), accelerations, decelerations, peak speed, average metabolic power, metabolic distance, dynamic stress load (DSL), relative distance, and speed intensity. The standardized intermitted running protocol used was a Yo-Yo intermittent recovery level 1. This study reported that Apex interunit analysis did not show any significant difference (delta difference and 95% confidence interval [CIs]) in total distance = 2.6 (−2.6; 7.9) m, HSR = 3.2 (−0.2; 6.8) m, accelerations = 0.09 (−0.9; 1.1), decelerations = 0.3 (−0.4; 1.1), peak speed = 0.02 (−0.03; 0.07) m·s−1, average metabolic power = 0.01 (−0.02; 0.04) W·kg−1, metabolic distance = 0.9 (−6.2; 8.0) m, DSL = 2.8 (−5.6; 10.7) au, relative distance = 0.14 (−0.19; 0.47) m·min−1, and speed intensity = 0.21 (−0.21; 0.64) au. All metrics presented a delta d between trivial to small. The interunit intraclass correlation coefficient (ICC) was good or excellent for all metrics, with the exception of DSL, which was considered questionable. In conclusion, this study reports that all the metrics analysis in this study presents a low interunit bias and high reliability (ICC), with the exception of DSL.

The Analysis of Physical Performance During Official Competitions in Professional English Football: Do Positions, Game Locations, and Results Influence Players' Game Demands?

“…Global positioning systems (GPS) and GNSS are very commonly used wearable technology in sport (2,11). Although the terms are sometimes used in the same way, actually, GNSS devices can use navigational satellites from other networks beyond the GPS system (satellite-navigation system owned by the U.S. government), therefore, by using more satellites, increases its accuracy and reliability (6).…”

“…Before each warm-up session (e.g., 15 minutes), the GNSS Apex units were turned on to allow the units to track an adequate number of satellites. The devices were worn in a custom-made vest and worn under the team's jersey, and the same units were worn by the same players to avoid issues with the interunit reliability (6,11). These units reported the number of satellites tracked that ranged between 17 and 23; average horizontal dilution of precision was 0.64 ± 0.22, which is in line with previous literature (4).…”

“…The reliability (interunit) during sprinting actions (range: 5–30 m) was excellent (intraclass correlation coefficient = 0.99), with a typical error of measurement of 1.85% (4). Very recently, a research reported that total distance, HSR, peak speed, accelerations, decelerations, and metabolic distance are reliable metrics using GNSS Apex during intermittent running activities (11).…”

Monitoring Readiness to Train and Perform in Female Football: Current Evidence and Recommendations for Practitioners

“…42 Sprint testing can be performed using timing-gates or global navigation satellite system to assess average and peak speed, respectively. 43,44 However, its relevance as a readiness assessment in female footballers may be questioned, given that (as previously mentioned) their sprint performance may already be recovered by 72 hours postmatch. 29 Given the lack of a complete description of the recovery time course in female footballers though, 29 more evidence is needed in such readiness (physical performance) measures.…”

“…45 However, further research are needed about the reliability of these specific metrics and about their validity to assess readiness in female football players before their implementation. 19,43 Practitioners could also use HR assessments outside of the training environment as measures of readiness, given they present an indicator of the autonomic nervous system. 47 HRV refers to the variation in time between consecutive R-to-R intervals, which provides information on the parasympathetic and sympathetic contributions to resting and postexercise modulation of HR.…”