To investigate the effect of the proposed law changes (ELV) in Rugby Union on the physical demands of the players when compared to existing rules.
Portable Global Positioning Systems (GPS) were worn by players in numerous positions (e.g. Prop, Hooker, Lock, No. 8, No. 7, Half-back, Wing, Fullback etc) during competitive rugby games. The players were competing in the Air New Zealand Cup (Premier Provincial 1st XV [Existing Rules - ANZC]) or the Provincial Development Competition (Provincial 2nd XV [New Rules - ELV]). Players were often replaced (substituted) before the end of games (normally during the second half) and therefore the data will be presented in “first half” analysis or “per minute” analysis. The GPS recorded distance covered, time and velocity. This was downloaded and is summarised below.
The Forwards covered 2949m (± 239m) and 2974m (± 428m) during the first half of ANZC and ELV games respectively (Means ± SD; Figure 1). In comparison the Backs covered 3321m (± 232m) and 3461m (± 191m) during the first half of ANZC and ELV games respectively (Figure 1).
Forwards covered 8m per minute more during the first half of the ELV games compared to ANZC games (75 ± 7 m/min ELV vs. 67 ± 5 m/min ANZC). Similarly the Backs covered 6m per minute more during ELV games compared to ANZC games (82 ± 4 m/min ELV vs. 76 ± 3 m/min ANZC). Metres per minute for the whole game showed similar trends (Forwards: 75 ± 7 m/min ELV vs. 65 ± 4 m/min ANZC; Backs: 80 ± 4 m/min ELV vs. 74 ± 4 m/min ANZC).
The distance covered running at “high intensity” (above 70% maximum predetermined running speeds: Tight Five Forwards 28km/h; Loose Forwards and Half Backs 30km/h; Backs 32km/h) for a whole game was greater during ANZC games than ELV games for forwards (142 ± 110m ANZC vs 104 ± 72m ELV) and backs (420 ± 73m ANZC vs 418 ± 193m ELV).
Mean distance covered during the first half of ELV Trial Games and ANZC Games in 2007. Forwards playing ELV rules (n=7 in 3 games) covered 1% more distance than forwards in ANZC games (n=4 in 3 games). Backs playing ELV rules (n=9 in 4 games) covered 4% more distance than backs in ANZC games (n=5 in 3 games).
Average distance covered per minute during ELV Trial Games and ANZC Games in 2007. Forwards playing ELV rules (n=7 in 3 games) covered 15% more distance per minute than forwards in ANZC games (n=4 in 3 games). Backs playing ELV rules (n=9 in 4 games) covered 8% more distance per minute than backs in ANZC games (n=5 in 3 games).
Average distance covered per game above 70% predetermined maximum running speed during ELV Trial Games and ANZC Games in 2007. Forwards playing ANZC games (n=4 in 3 games) covered 37% more “high intensity” distance than forwards in ELV games (n=7 in 3 games). Backs playing ANZC games (n=5 in 3 games) covered 0.5% more “high intensity” distance than backs in ELV games (n=9 in 4 games).
The data was collected across different positional groups and using different players.
Data must be interpreted with caution as comparisons are being made between two different levels of player/games (ANZC & Provincial Development Teams).
The data was collected across three to four different games (e.g. different opposition, different conditions, different game plan etc).
“High Intensity” running speeds (above 70%) are a prediction only.