title: The use of individualized speed and intensity thresholds for determining the distance run at high-intensity in professional soccer.
abstract: As with other match analysis systems, ProZone uses an absolute speed threshold to identify running speeds at "high-intensity". In this study, we examined the use of an individualized high-intensity speed threshold based on the speed at the second ventilatory threshold (VT(2speed)) for assessment of the distance run at high-intensity during matches. Ten professional soccer players completed a maximal treadmill test to determine VT(2speed). Match data were identified by means of the ProZone match analysis system. The distances run at high-intensity during matches were calculated using the default value (19.8 km . h(-1)) and VT(2speed). Differences between VT(2speed) and the default were analysed using a non-parametric median sign test. The distances run at high-intensity were compared with a paired t-test. The median VT(2speed) was 15 km x h(-1) (range 14-16 km x h(-1)), which was less than the default (P < 0.01). Mean distance run at high-intensity based on the default and VT(2speed) was 845 m (s = 296) and 2258 m (s = 707), respectively [mean difference 1413 m; P < 0.001 (95% CI: 1037-1789 m)]. The high-intensity running speeds based on the second ventilatory threshold are substantially less than that used as the default within the ProZone match analysis system, thus the distance run at high-intensity can be substantially underestimated.
authors.affiliation: Sport, Health and Exercise Science, The University of Hull, Kingston upon Hull, UK. g.abt@hull.ac.uk
authors.forename: Grant
authors.initials: G
authors.lastname: Abt
authors.forename: Ric
authors.initials: R
authors.lastname: Lovell
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D012420:Running / Q000502:physiology*; D012916:Soccer; D013647:Task Performance and Analysis; D055815:Young Adult