Are Rugby Players Getting Bigger?

By Ben Nurse

Death, taxes, Saracens being good. Just as the sky is blue and the grass is green, some things in this life are for certain and none more so than amateur-era rugby players constantly reminding you how much better the game was in their day.

Among other complaints such as, there is too much kicking, players don’t run the ball as much and of course the tried and tested, ‘the game’s gone soft’, one of the most common criticisms is that the players are just far too big these days. It decreases space, it increases danger, it makes the game boring, whatever the consequence, they are just too big and are getting bigger every year.

So how much truth is in this?

Our goal is to find out: firstly, if rugby players are getting bigger, if so, then how much bigger are they getting? And finally, what does this mean for the future?

To do this we have to draw on a bonified study with a proven conclusion to act as a basis, using these figures and the thesis, we can evaluate the facts behind this apparently commonly held truth, that rugby players are getting bigger, rather than the assumptions.

The study by Dr Ross Tucker, et al, from 2019, took the mass of every rugby player from every Rugby World Cup from 1991-2019 and plotted the data to analyse the size increase.

The conclusion found: “The body mass of men’s players has stabilised after initial increases following professionalisation. Player body mass may be approaching a plateau, beyond which no further performance advantages occur.”

Tucker actually found that, despite most citing professionalism as the biggest factor in player size increase, that the biggest increase in player mass occurred between 1991 and 1995, while professionalisation first began in summer 1995. Furthermore, although the total increase in T1 players between 1991 and 2019 totalled 9.7%, this increase occurred almost entirely up to 2015, when the numbers begin to plateau.

However, this is where it gets technical. As Tucker split his data into T1, T2 and Pacific Island players, the data actually shows a decrease in the size of Pacific Island backs, from a mean mass of 93.4 in 1999, to 97.5 in 2007, back down to 92.8 in 2019.

What does this mean? Well because the average Pacific Islander was heavier than the average T1 or T2 player in 1991 but now they have all met at the same weight in 2019, the former through a decrease in size, the latter through an increase, this suggests an optimal weight for rugby. The perfect mass for a rugby player.

Bearing this in mind, look at the average weight of every squad at Rugby World Cup 2023, what do you see?

It’s incredibly uniformed. Just 11kg between the heaviest and lightest squad and if we take out those outliers, just 8kg between 2^nd and 19^th.

What else do you notice? Well while the average T2 player used to be lighter than the average T1 player (the professionals at the time) that gap has now narrowed and almost been completely shattered.

With increased funding, exposure and experience, T2 teams are beginning to compose squads with the same size profile as the world’s most elite sides.

It is safe to assume that, with the increase in sophistication and understanding globally of conditioning and and sport science, a general consensus is being found on how big a rugby player should be.

You may argue, ‘but Tonga and Samoa are still top, and Portugal are still bottom’. That is because the gap is still narrowing and will continue to narrow.

The other problem with this being presented as a positive is that rugby does not want to lose its ‘a shape for all sizes’ mantra, we don’t want a uniform sport, we want a sport that can be played by very big men and by very small men.

Well, don’t worry.

This graph shows the range in sizes of every player in each squad, from your Faf de Klerk’s to your Ben Tameuifuna’s and, as you can see, there is not link whatsoever between having a squad that is all the same size and being successful, on the contrary, South Africa and New Zealand, our two finalists, have two of the biggest ranges in size.

This graph also shows that a massive deficit in size is still occurring on rugby’s biggest stage, with a whopping 83kg between the heaviest player, Tameuifuna at 151kg and Romania’s Vladu Bocanet at 68kg.

83kg, by the way, is the weight of England’s Alex Mitchell, so there is a whole Alex Mitchell’s worth of weight separating the heaviest and lightest players at Rugby World Cup 2023, truly a fact to be celebrated.

So, what does this data mean for the future, can we predict what the average rugby player will look like and weigh at the next Rugby World Cup in 2027?

Yes, absolutely we can.

To do this, we must take the Pacific Islanders as our metaphorical ‘guinea pigs’, as they began to plateau in size increase first, circa 2007, while the T1 and T2 nations have still been increasing in size but exponentially slower, clearly leading to an inevitable plateau.

So, if the mean mass for a Pacific Island back was 92.8 in 2019 and 91.6 and 89.9 for T1 and T2, respectively, expect them all to meet in the middle at around 92-93.

Similarly, for the forwards, T1 players are increasing in size around 8 years behind the Pacific Islanders, who had a mean mass of 113 in 2007, while T1 hit that number in 2019 after increasing from 110. So, if the Pacific Islander forwards had a mean mass of 115 in 2019, expect T1 and T2 forwards to aim to hit that figure in 2027, while the Pacific Islanders should stay where they are.

In conclusion, rugby players ARE getting bigger. However, the plateau in size increase is slowly becoming exponentially more significant and very soon we will see rugby teams find the optimal size for a rugby player and this is where the size increase will cease. Of course, this will not last forever, eventually the game will change in some way to necessitate either a size increase or decrease. Maybe World Rugby will make the game 13 v 13, maybe tries scored from the attacking team’s 22 will count for double points, leading to a metaphorical ‘arms race’ for faster players. Whatever that may be we cannot predict it, we can just hope that by then rugby is still indeed, a game for all shapes and sizes.