The worst case scenario: Locomotor and collision demands of the longest periods of gameplay in professional rugby union.

A number of studies have used global positioning systems (GPS) to report on positional differences in the physical game demands of rugby union both on an average and singular bout basis. However, the ability of these studies to report quantitative data is limited by a lack of validation of certain aspects of measurement by GPS micro-technology. Furthermore no study has analyzed the positional physical demands of the longest bouts of ball-in-play time in rugby union. The aim of the present study is to compare the demands of the single longest period of ball-in-play, termed "worst case scenario" (WCS) between positional groups, which have previously been reported to have distinguishable game demands. The results of this study indicate that WCS periods follow a similar sporadic pattern as average demands but are played at a far higher pace than previously reported for average game demands with average meters per minute of 116.8 m. The positional differences in running and collision activity previously reported are perpetuated within WCS periods. Backs covered greater total distances than forwards (318 m vs 289 m), carried out more high-speed running (11.1 m·min-1 vs 5.5 m·min-1) and achieved higher maximum velocities (MaxVel). Outside Backs achieved the highest MaxVel values (6.84 m·sec-1). Tight Five and Back Row forwards underwent significantly more collisions than Inside Back and Outside Backs (0.73 & 0.89 collisions·min-1 vs 0.28 & 0.41 collisions·min-1 respectively). The results of the present study provide information on the positional physical requirements of performance in prolonged periods involving multiple high intensity bursts of effort. Although the current state of GPS micro-technology as a measurement tool does not permit reporting of collision intensity or acceleration data, the combined use of video and GPS provides valuable information to the practitioner. This can be used to match and replicate game demands in training

Application of Individualized Speed Thresholds to Interpret Position Specific Running Demands in Elite Professional Rugby Union: A GPS Study

<div><p>A number of studies have used GPS technology to categorise rugby union locomotive demands. However, the utility of the results of these studies is confounded by small sample sizes, sub-elite player status and the global application of absolute speed thresholds to all player positions. Furthermore, many of these studies have used GPS units with low sampling frequencies. The aim of the present study was to compare and contrast the high speed running (HSR) demands of professional rugby union when utilizing micro-technology units sampling at 10 Hz and applying relative or individualised speed zones. The results of this study indicate that application of individualised speed zones results in a significant shift in the interpretation of the HSR demands of both forwards and backs and positional sub-categories therein. When considering the use of an absolute in comparison to an individualised HSR threshold, there was a significant underestimation for forwards of HSR distance (HSRD) (absolute = 269 ± 172.02, individualised = 354.72 ± 99.22, p < 0.001), HSR% (absolute = 5.15 ± 3.18, individualised = 7.06 ± 2.48, p < 0.001) and HSR efforts (HSRE) (absolute = 18.81 ± 12.25; individualised = 24.78 ± 8.30, p < 0.001). In contrast, there was a significant overestimation of the same HSR metrics for backs with the use of an absolute threshold (HSRD absolute = 697.79 ± 198.11, individualised = 570.02 ± 171.14, p < 0.001; HSR% absolute = 10.85 ± 2.82, individualised = 8.95 ± 2.76, p < 0.001; HSRE absolute = 41.55 ± 11.25; individualised = 34.54 ± 9.24, p < 0.001). This under- or overestimation associated with an absolute speed zone applies to varying degrees across the ten positional sub-categories analyzed and also to individuals within the same positional sub-category. The results of the present study indicated that although use of an individulised HSR threshold improves the interpretation of the HSR demands on a positional basis, inter-individual variability in maximum velocity within positional sub-categories means that players need to be considered on an individual basis to accurately gauge the HSR demands of rugby union.</p></div

ABS vs IND HSR demands of forward position sub-categories.

<p>ABS = absolute high speed running threshold (5 m·s^-1); IND = individual high speed running threshold (60% vMAX); HSR = high speed running; HSRD = high speed running distance; HSR% = % of total distance at HSR; HSRE = number of HSR efforts.</p><p>* = significantly different from ABS (p < 0.001);</p><p>** = significantly different from ABS (p < 0.01);</p><p>*** = significantly different from ABS (p < 0.05).</p><p>ABS vs IND HSR demands of forward position sub-categories.</p

ABS vs IND HSR demands of back position sub-categories.

<p>ABS = absolute high speed running threshold (5 m·s^-1); IND = individual high speed running threshold (60% vMAX); HSR = high speed running; HSRD = high speed running distance; HSR% = % of total distance at HSR; HSRE = number of HSR efforts.</p><p>* = significantly different from ABS (p < 0.001);</p><p>** = significantly different from ABS (p < 0.01);</p><p>*** = significantly different from ABS (p < 0.05).</p><p>ABS vs IND HSR demands of back position sub-categories.</p

Forward vs back running game output.

<p>Forward vs back running game output.</p

Forward vs back IND HSR demands.

<p>IND = individual high speed running threshold (60% vMAX); HSR = high speed running; HSRD = high speed running distance; HSR% = % of total distance at HSR; HSRE = number of HSR efforts; HSRDpm = high speed running distance per minute; HSREpm = high speed running efforts per minute.</p><p>Forward vs back IND HSR demands.</p

Descriptive statistics on the IND HSR output of individual forwards players.

<p>IND = individual high speed running threshold (60% vMAX); HSR = high speed running; HSRD = high speed running distance; HSR% = % of total distance at HSR; HSRE = number of HSR efforts; HSRDpm = high speed running distance per minute; HSREpm = high speed running efforts per minute.</p><p>Descriptive statistics on the IND HSR output of individual forwards players.</p

Forward vs back ABS HSR demands.

<p>ABS = absolute high speed running threshold (5 m·s^-1); HSR = high speed running; HSRD = high speed running distance; HSR% = % of total distance at HSR; HSRE = number of HSR efforts; HSRDpm = high speed running distance per minute; HSREpm = high speed running efforts per minute.</p><p>Forward vs back ABS HSR demands.</p

ABS vs IND HSR demands of forwards and backs.

<p>ABS = absolute high speed running threshold (5 m·s^-1); IND = individual high speed running threshold (60% vMAX); HSR = high speed running; HSRD = high speed running distance; HSR% = % of total distance at HSR; HSRE = number of HSR efforts.</p><p>ABS vs IND HSR demands of forwards and backs.</p