Rugby and American football are two of the most physical team sports in the world. We looked at the numbers to work out which is the more demanding of the two.

As most athletes know, playing a team sport means you're competitive in every sense of the word, and listening to a rugby player and an American footballer argue is the perfect example.

There's no denying that both are among the toughest team sports around. (Yes, Australian rules, we see you glaring.) And if you've heard players from both sides argue about which is harder, you'll know it seems a pretty close debate.

Or so it seems.

Thanks to sports science, we can now get past opinions and compare the data. In this article we compare rugby players and American footballers across several categories to settle which is the more demanding sport.

A brief history of rugby

Modern rugby traces its roots to Rugby School in Warwickshire. According to the legend, in 1823 a pupil called William Webb Ellis picked up the ball and ran with it. Whether or not it really happened, two centuries later rugby is played and watched all over the world.

There are several forms of rugby, but in this article we focus on rugby union and rugby league. They're similar, with a few key differences. Union is played 15-a-side and league 13-a-side, and league was designed for a faster, more continuous game, so many consider it the more gruelling of the two.

The rise of American football

American football is a younger sport, developed in the 19th century, and anyone who has seen a game or held the ball can tell it grew (at least partly) out of rugby. The first college game was played in 1869, and the basic rules of the modern game were shaped in the 1880s by Walter Camp, a Yale player who started out in the rugby-style game.

Today American footballers wear helmets, shoulder pads and other protective gear. The quarterback is usually the most important player on the field, throwing forward passes to the receivers.

In rugby you can only pass backwards, and players wear little or no protection: perhaps some light padding, a gumshield and, for some, a scrum cap.

And if you think a scrum cap offers much protection (other than an attempt to prevent cauliflower ears), you might be better off growing an afro like Colin Charvis.

Head-to-head comparison

American footballers are often called the toughest athletes around, so it's time to let the numbers do the talking. Below we compare the two sports across five categories and pick a winner in each.

Size

At face value this looks like an easy win for American football. Some NFL players weigh well over 300 lb (136 kg), so the biggest players in football are probably heavier than the biggest in rugby.

What's interesting is that across positions, the differences in height and weight are actually fairly similar, at least according to research comparing elite rugby players with top-level college footballers.

In one New Zealand Super Rugby squad with an average age of around 26, the average height was 187.6 cm and the average weight 108 kg. The college football players studied were 186 cm and also 108 kg on average, but with much more variation in body weight.

So although there are more extreme body sizes in American football, the averages are close, and rugby union players may be slightly taller on average in this (admittedly small) comparison.

Rugby league players need fewer specialist body types for lineouts and scrums and more all-round running fitness, so they tend to be a little shorter and around 8 to 10 kg lighter than union players. Size brings benefits and costs that are unique to each sport, which is what we'll look at next.

Result: draw. Just. The average college football player still has some growing to do, being several years younger than the professional rugby players he was compared with.

Speed and strength

Working out who runs fastest is tricky. Top speed is a good guide, but American footballers play in heavy padding.

The best comparison is the NFL Scouting Combine, where players do a series of timed drills without pads. For a rugby comparison we can use Jarryd Hayne, the Australian rugby league star who signed for the San Francisco 49ers in 2014 and played in the NFL in 2015.

The fastest 40-yard dash (36.6 metres) recorded at the combine is 4.21 seconds, set by Xavier Worthy in 2024. Hayne was reported to have run the 40 in around 4.5 seconds in his NFL workouts, which is also extremely fast.

Taking a wider view across all positions, research on elite rugby union players found an average 40-metre time of around 5.3 seconds, while NCAA Division I footballers averaged 4.74 seconds over 40 yards. 40 metres is about 4 metres longer than 40 yards, and the tests were done under different conditions, so the gap isn't as big as it looks. Even so, American footballers seem to have the upper hand here.

That's not surprising. Football is built on short, all-out bursts, with a heavy focus on strength, speed and power. Rugby players also have to build endurance and a much wider range of skills.

It also means American footballers tend to be stronger. One study of NCAA Division I players reported an average bench press of 160 kg and squat of 235 kg, against around 140 kg and 190 kg in an elite rugby squad. Again, the testing conditions may not be directly comparable, but given that college players haven't reached their physical peak, it points to American football in this category.

Winner: American football.

Endurance and mental fatigue

Toughness isn't only about big hits and speed. How hard a game is to play depends on stamina, endurance and staying switched on.

Elite rugby union players typically cover around 5 to 7 km (roughly 3 to 4.5 miles) in a match, depending on position, and play for up to 80 minutes, with the ball in play for around 35 to 40 minutes of that.

In the NFL, a widely quoted Wall Street Journal analysis found that the ball is actually in play for only around 11 minutes of a typical game, in short bursts with long breaks between plays. Individual players run far less than rugby players, and specialist units rotate on and off the field.

Rugby players run more, hit more and have to stay mentally switched on for far longer. They don't get to reset after every tackle: they have to get back up, get back in the defensive line, make the last-ditch tackle and cover the kick over the top.

Picture this (it happens all the time). It's the last five minutes and the opposition boot a monster kick downfield. It's a footrace. The ball lands in your 22 and they win it back.

You make the tackle, get back to your feet to compete for the ball, and get cleared out by their forwards. They play it fast. You HAVE to get up and back in line, only to see their 120 kg prop running straight at you. Another big hit.

Now you're on your own try line, defending phase after phase. There's no breather and no time to think. Your body is on the line until the final whistle.

VO2 max is a measure of how well the body uses oxygen to produce energy, and a good indicator of endurance. Professional rugby players in both codes commonly record VO2 max scores above 50 ml/kg/min, with league players often in the mid-50s.

Comparable data for American footballers is harder to find. Some players record similar scores to rugby players, but on average, across all positions, they tend to be lower, which again isn't surprising given the demands of the game.

Winner: rugby.

Tackle forces

Both sports are famous for big hits, but who takes the hardest ones? First, some basics.

Collisions are often measured in g, units of acceleration. One g is the acceleration due to gravity at the Earth's surface, about 9.8 metres per second per second. To put it in perspective, a fast roller coaster puts around 3 to 6 g through your body.

Many things affect how hard a tackle is. Studies using sensors have recorded rugby players experiencing impacts of more than 10 g many times in a game, while American footballers' helmet sensors regularly record head impacts above 20 g, with the biggest hits far higher. The two sports measure in different ways (helmet sensors versus body-worn units), so the comparison isn't perfect, but football players appear to take bigger individual hits, helped by running full-speed into each other with the protection of pads and helmets.

Winner: American football.

Tackles per game and injury risk

The force of the biggest hits is one thing, but the number of collisions matters too.

In the NFL, the league's leading tacklers usually average somewhere around eight to ten tackles a game over a season. In rugby union, back-rowers and centres regularly make 15 or more tackles in a Test, and the top tacklers in big matches can make well over 20.

On top of tackles, rugby has rucks, mauls and scrums. American football has plenty of collisions too, with blocking on every play, but because rugby is continuous for 40 minutes a half and every player is involved in contact, there are more collisions per player across a game.

With contact comes injury risk. Comparing sports directly is difficult, because of the differences in playing time and the way injuries are recorded. A widely cited meta-analysis of professional men's rugby union (Williams and colleagues, 2013) found around 81 injuries per 1,000 player-hours of matches. Studies of the NFL have reported game-injury rates in the region of 60 to 70 per 1,000 athlete exposures, where one exposure is one player taking part in one game or practice. A thousand player-hours is the equivalent of around 750 full 80-minute rugby matches, which suggests an injury is more likely in a rugby match than in an NFL game. More fatigue plus more contacts mean more chances to get hurt, even if each individual collision is smaller.

The type of injury matters too. The long-term effects of head injuries have been well documented in American football and, increasingly, in rugby, and both sports have changed their laws and protocols in recent years to reduce head impacts.

All in all, deciding which sport is more dangerous is difficult. But given the repeated collisions and the effect of accumulated fatigue, we have to say rugby is harder on the body overall. Whether you can call that "winning" is another matter, and it's encouraging to see both sports taking player welfare increasingly seriously.

Winner: rugby.

Declaring a winner

On points it's close, but a winner has to be picked. Because of the stamina it demands and its continuous play, we're going with rugby as the tougher sport overall.

American football may have the biggest hits and the fastest players, but the stop-start nature of the game isn't comparable with 80 minutes of near-continuous intensity in rugby.

But really, who cares?

Both sports hit hard and are played by some of the best athletes in the world. What really matters is your love for your own sport. And if you play rugby and want to borrow from the gridiron, start with our NFL drills that will help you in rugby.

Sources

  • Williams S, Trewartha G, Kemp S, Stokes K. A meta-analysis of injuries in senior men's professional Rugby Union. Sports Medicine, 2013; 43(10): 1043 to 1055. PubMed 23839770
  • Biderman D. "11 Minutes of Action." The Wall Street Journal, January 2010 (analysis of ball-in-play time in NFL games).
  • NFL Scouting Combine records: Xavier Worthy, 4.21-second 40-yard dash, 2024.