Monday, December 1, 2008

Give Blood, Play...Rugby or American Football?

Athletes across all sports are very competitive and often argue about things that may seem ridiculous to a non-athlete bystander. Bragging that their sport is best, athletes will claim anything from including that their sport isthe best in the world, and that their players endure the most hits. In fact, one of the questions most controversial among athletes is who hits harder: rugby players or football players? Is a rugby tackle more forceful than a football one? Advocates from each side will claim that they have the best hits, but which case will science back up?

A study was done by the crew of FSN Sport Science that tested the above question. The data that they gathered can be summarized as follows. A rugby player hits with a force of approximately 1600 N, while a football player tackles with about 3 times that force (≈4800 N). However, a football player may only get around 5 good hits a game, while a rugger may get up to 20. This additive effect shows that over the course of a game, the amount of work (Work= Force times the change in distance) exerted on tackled players is about the same in both sports.

It is also interesting to keep in mind that football players are fully padded, which gives a sense of psychological security; while rugby players aren’t allowed even the security of having a cup. Also important to note is the fact that the weight of the pads that football players wear contribute to the strength with which they hit because F=ma. And while wearing pads provides some comfort, it also functions in spreading the force of impact. The pads of football players diffuse the impact so the entirety of the hit is not in one localized area. Conversely, because there are no pads in rugby, players are much more likely to break bones because the force of hit will be pinpointed in one area. What all this means is that ruggers feel more of the pressure (P=Force/Area)applied to them, as well as a larger impulse (Impulse=Force times change in time); while football players don’t feel the impulse of a rugby player because their pads spread the force applied out over a larger area. The remaining pressure felt is not as acute either because the force of impact is spread over a larger surface area by padding.

Despite these facts that individual football players do hit harder, many rugby tackles are done by more than one person, which means that for the tackled rugger, there is additive forces being applied. Also important to recognize is the fact that it’s not really fair to compare the two sports. Other than contact being made, and a similar ball being used, there isn’t much in common between the two sports. The force of the tackling differs because the method of tackling is different. And the methods are different because the purpose for tackling is different. And while getting hit is tiring, there are other factors to keep in mind. Football players may have to make contact during the line of scrimmage after the initial snap, but play stops every time a player is tackled, the ball hits the ground, the ball goes out of bounds, when possession changes, when a player is injured, or whenever a referee has to explain the reason for a penalty, which happens often. This allows time for players to regroup and maybe grab some water. The change of possession also means that a whole new set of players comes out onto the field.

On the other hand, play is almost fully continuous in rugby. Even if a player is injured, play will continue until it is appropriate to stop. The only exception to this is when the injury is too major to be ignored. There are no timeouts, and only 7 substitutions can be made throughout the 80 minute game (20 minutes longer than a football game). The same 15 players play both offense and defense, which means the same players are tackling, rucking, mauling, and engaging in scrums. And no matter how sore a rugger’s arms may be from tackling or being tackled, they still must be able to lift one of their own during lineouts.

So in the end, it comes down to a personal preference. Too many times the question boils down to a European vs. American issue. But if you were to go purely by country, then you cannot fully appreciate either sport. So make of the information what you will and decide for yourself which is more intense: football or rugby?

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