Issuu on Google+

Forwards vs Backs

BODIES OF EVIDENCE “ DR JODI RICHARDSON Sports Scientist

Though extra body fat has been suggested by some to have a possible cushioning effect for players against injury, it will ultimately reduce performance by reducing speed and muscular power

PHOTOS: GETTY IMAGES

A

S A collision sport, sprinting and tackling are fundamental to rugby league, a game that is tough physically, no matter which position you play. But different playing positions entail different physical demands and research is now giving us a better understanding of just how physically different backs and forwards are. Analysis of player movement patterns highlights the different demands on each position and, not surprisingly, forwards bare the brunt of significantly more tackles and collisions than backs. But backs are likely to do more free running than forwards. Other research has shown that the average distance covered by forwards is around 10km, while backs, such as Mitchell Pearce (right), cover an average of 8.5km per game. We know and love rugby league as a game dominated by short bursts of sprinting followed by heavy tackling after which some players can get a short recovery period. During this recovery time, these players are usually still moving but are only walking or jogging. Research reveals that in addition to travelling a greater average distance per game than backs, forwards don’t get as much rest. One study showed that league forwards have up to half as much recovery time between intense efforts compared with backs but in an ever-changing game, this gap may no longer be as wide. The typical battery of tests that are used by sports scientists measure physical fitness and performance in a range of areas that are relevant to the skills of rugby league. These tests include measures

of player height; body weight; body fat; vertical jump to measure muscular power; maximum weight lifted for one repetition for a squat or bench press to determine muscular strength; speed over 10, 20 and 40 metres; agility to measure how quickly a player can change direction; and a fitness test that requires players to run continuously until fatigue to measure their aerobic fitness. The average body weight of a senior rugby league forward is estimated between 95-105kg with larger forwards

averaging around 115kg, while backs average around 85-95kg. Forwards typically carry more body fat than backs. It makes sense given the demands on forwards to tackle and break tackles, where greater size and mass make you harder to stop, and better at halting the forward progress of attacking players. Interestingly, Dr Tim Gabbett, a leading researcher and sports scientist for the Brisbane Broncos, reports in his research that body mass is an important physical characteristic that determines whether a player will cut it in the NRL. Dr Gabbett raises the question whether

players are positioned on the field based on their physical make-up or whether players have a particular physical make-up that develops based on the demands of the position they play. He comments that “physical size, strength and speed most likely result in a player being positioned accordingly and that most players are probably channelled this way from junior competitions”. Though forwards have been typically known for being heavier with more body fat than backs, that could all change now. Reduced interchanges requires forwards to have the endurance to play for longer periods of time. Carrying more weight costs more energy and though extra body fat has been suggested by some to have a possible cushioning effect for players against injury, it will ultimately reduce performance by reducing speed and muscular power. That’s why a player such as Parramatta’s Mark Riddell (below left) would have worked so hard in the off-season to shed some kilos. Dr Gabbett reports that high muscular strength and power are required to provide fast play-the-ball speed and leg drive in tackles, as well as assist players with the large amounts of wrestling that occur in the tackle contest. Despite different physical demands on forwards and backs, in general, aerobic fitness levels are similar between these players. Though the game does not require players to run long distances, aerobic fitness is essential to aid player recovery between intense sprinting bouts. It is likely that some physical characteristics are similar between forwards and backs partly as a result of a similar training time spent developing them. Though player training is sometimes conducted as one group, Dr Gabbett comments that this is not always the case. “Most clubs will separate forwards and backs for various parts of training; particularly because players need to have a chance to work against other players of similar size and strength to get a decent training effect and you don’t want smaller players to become unduly fatigued or injured.” ●


Rugby League Week - Bodies of Evidence