The Reliability and Validity of a Soccer-Specific Nonmotorised Treadmill Simulation (Intermittent Soccer Performance Test)

Abstract

This study investigated the reliability and validity of a novel nonmotorised treadmill (NMT)-based soccer simulation using a novel activity category called a "variable run" to quantify fatigue during high-speed running. Twelve male University soccer players completed 3 familiarization sessions and 1 peak speed assessment before completing the intermittent soccer performance test (iSPT) twice. The 2 iSPTs were separated by 6-10 days. The total distance, sprint distance, and high-speed running distance (HSD) were 8,968 ± 430 m, 980 ± 75 m and 2,122 ± 140 m, respectively. No significant difference (p > 0.05) was found between repeated trials of the iSPT for all physiological and performance variables. Reliability measures between iSPT1 and iSPT2 showed good agreement (coefficient of variation: <4.6%; intraclass correlation coefficient: >0.80). Furthermore, the variable run phase showed HSD significantly decreased (p ≤ 0.05) in the last 15 minutes (89 ± 6 m) compared with the first 15 minutes (85 ± 7 m), quantifying decrements in high-speed exercise compared with the previous literature. This study validates the iSPT as a NMT-based soccer simulation compared with the previous match-play data and is a reliable tool for assessing and monitoring physiological and performance variables in soccer players. The iSPT could be used in a number of ways including player rehabilitation, understanding the efficacy of nutritional interventions, and also the quantification of environmentally mediated decrements on soccer-specific performance.

Exposure to hot and cold environmental conditions does not affect the decision making ability of soccer referees following an intermittent sprint protocol

“…Data from the iSPT displays reductions in total distance covered and distance covered at high intensities during the second 45 min of a 90 min protocol (Aldous et al, 2013), similar to the field data observed in elite referees (Krustrup and Bangsbo, 2001; Reilly and Gregson, 2006) and players (Mohr et al, 2003; Barros et al, 2007; Bradley and Noakes, 2013). All variables associated with internal and external load in response to iSPT (Aldous et al, 2013), were shown to be reliable, and valid in comparison to match play data. Therefore, it is recommended that the present experimental design be repeated with the protocol employed (Drust et al, 2000) replaced with iSPT (Aldous et al, 2013), or a similar appropriately constructed protocol (Williams et al, 2010).…”

“…Lack of individualization in physiological load, likely produced differential internal and external loads within subjects. The mean average HR across conditions in the present study (COLD: 138 ± 5; CONT: 146 ± 6; HOT: 151 ± 5), compared to 165 bpm from soccer match play (Catterall et al, 1993) and 167 bpm from an appropriately valid and reliable treadmill based soccer simulation (Aldous et al, 2013) respectively, suggests that physiological load in the present study was not indicative, thus not valid, in light of the values typically seen in soccer match play (Catterall et al, 1993; Castagna et al, 2007; Krustrup et al, 2009; Bradley and Noakes, 2013). Further concern is raised by the highest mean RPE recorded throughout HOT (30°C) in the present study being 15 (HARD), whereas repeated sprint protocols typically elicit RPE >18 (Drust et al, 2005).…”

“…A recently published protocol utilizing a non-motorized treadmill based intermittent soccer-specific performance test (iSPT) (Aldous et al, 2013) provides the individualized variance (e.g., reduction in distance covered between 1st and 2nd halves) observed in real-life match play in soccer players (Mohr et al, 2003; Barros et al, 2007; Bradley and Noakes, 2013) and referees (Catterall et al, 1993; Krustrup and Bangsbo, 2001), which was absent in the utilized protocol (Drust et al, 2000). Data from the iSPT displays reductions in total distance covered and distance covered at high intensities during the second 45 min of a 90 min protocol (Aldous et al, 2013), similar to the field data observed in elite referees (Krustrup and Bangsbo, 2001; Reilly and Gregson, 2006) and players (Mohr et al, 2003; Barros et al, 2007; Bradley and Noakes, 2013).…”

Physical and psychomotor performance of Australian football and rugby league officials during a match simulation

“…The study demonstrated no differences in psychomotor performance across the simulation, despite significant declines in the total distance covered and HSR distance. These reductions in physical performance are in agreement with various time-motion literature on similar team sport officials during actual match play and laboratory-based simulations (Aldous et al, 2014). While the target speed was consistent throughout the simulation, the reduction in the physical capacity to reach the targeted speeds is typical of accumulative fatigue that may limit HSR.…”

The validity of endurance running performance on the Curve 3TMnon-motorised treadmill

“…Such treadmills may work by the act of pushing backwards on an inclined treadmill belt (Curve NMT, Woodway, Waukesha, WI, USA), or pushing backwards on a flat treadmill belt with the aid of a cable attached to the runner (Force NMT, Woodway, Waukesha, WI, USA). The Force NMT has demonstrated good reliability and validity for the assessment of sprint (Highton, Lamb, Twist, & Nicholas, 2012;Lakomy, 1987) and repeat sprint (Aldous et al, 2014;Sirotic & Coutts, 2008) intervals in the laboratory, where motorised treadmills are not appropriate due to restrictions on acceleration.…”