The animals you can't outrun - and the ones you can

Ever wondered if you could beat a bear or a horse in a race? What about a rat or a rhino? The answers may surprise you.

A few years ago, I was camping in the US, and a black bear happened to pass nearby. As I watched it nose around the camp, I wondered: if I needed to, could I outrun it?

Looking up bear speeds afterwards, the answer was clear: absolutely not. Apart from the fact that running away can trigger a chase response, so is not advised, black bears can reach up to 48km/h (30mph).

Ever since then though – especially while out for a jog in London – I've found myself asking: what animals could I beat in a foot race? What if I encountered a particularly mean squirrel or badger?

Only Noah could have staged a real animal Olympics, but scientists have measured the top running speeds of hundreds of creatures – squirrels and badgers, but also spiders, lizards, rodents, birds, large mammals, and many more. It turns out there are quite a few surprises in the data. 

So, which land animal would be your own closest competitor? And what would give the world's fastest humans a good race?

Over the decades, scientists have measured animals' top speed using differing methods: some more accurate (and ethical) than others. In the 1920s, one naturalist drove his car alongside pronghorn antelopes – North America's fastest land animal – firing gunshots in the air to keep them going. And in the 1980s, researchers realised they could place smaller animals like rats on treadmills.

Nowadays, though, technology like GPS trackers make the task easier, especially for recording animals in their natural habitat at real-world speeds. One recent study that tracked cheetahs in the wild showed they can reach 93km/h (58mph). Previous measurements were based on film recordings, or in one case, artificially inducing the cheetah to chase a hunk of meat held by a stopwatch operator riding in a 4x4.

Sometimes, though, simple methods have also worked fine. In another recent study, researchers measured what might be the world's fastest spider (Australia's brown huntsman) by simply nudging it and then video-recording it next to a ruler. While its average pace was around 7km/h (4.3mph), its top speed in bursts was a discomfiting 13km/h (8mph).

Over time, researchers have compiled these disparate scientific measurements into larger databases. One of them is biologist Myriam Hirt, now at the German Centre for Integrative Biodiversity Research in Leipzig, who compiled the running speeds of around 350 land animals. In 2017, she and her colleagues were investigating the question of how animal body mass affects their speed.

In principle, bigger animals with more muscle mass should be able to run the fastest. "It makes sense when you first think about it, but the data clearly shows that it doesn't work that way," Hirt says. "The largest species are not the fastest. No one knew why."

She and her colleagues concluded that the largest animals are constrained from reaching their hypothetical top speeds by the body mass they carry. "You need more time to get a big body moving at the same speed as a small one," she explains, in the same way that big planes need longer runways. (Or as anyone who has ever played Mario Kart will know: tiny Toad accelerates faster than bulky Donkey Kong.)

This slow take-off means that big animals begin to fatigue before they reach their top potential speed. "You only have a limited amount of energy available for acceleration. At some point you just collapse, because there's no energy left in your muscles," Hirt says.

The slow acceleration of big animals does also mean you might be capable of beating some of them in a race, especially over short distances. For example, an African bush elephant can reach a top speed of 35km/h (21.7mph), but they are slower than humans out of the blocks.

Another animal speed database compiled in 2020, which integrated statistics on animal acceleration, suggests the African bush elephant would reach its top speed in about 7.5 seconds. A back-of-the-envelope calculation suggests it would therefore run the 100m (328ft) in around 14 seconds. I doubt I could match that time myself, but according to running website Marathon Handbook, it'd be beatable for some well-trained adults. 

Olympic sprinter Usain Bolt could probably outrun the bush elephant easily – but even he would be overtaken by many other animals. If we are talking about simply comparing top sprint speeds – without the variable of mass and acceleration – Bolt's fastest pace during his world record run was around 44km/h (27-28mph). That's faster than the top speed of a white rhino (40km/h or 24.8mph), but not a grizzly or polar bear (48-50km/h or 30-31mph). And plenty of animals reach even faster top speeds.

The most famous sprinters are the cheetah (93km/h or 58mph), or ostrich (82.8km/h or 51.4mph), but some are lesser known. As a thin and lanky runner, I'd hoped that a giraffe might be my own closest animal competitor, but I was surprised to learn they can reach up to around 57-60km/h (35-37mph), so would crush me – and Bolt – in a sprint. The moose is pretty rapid too (55.4km/h or 34.4mph), as is the zebra (70.6km/h or 43.8mph) – and a reindeer can reach speeds of 80km/h (49.7mph). I suppose Santa would be pleased.

What about longer distances though? Sprinting is an anaerobic activity, requiring so-called fast-twitch muscle, explains former Olympian 1,500m runner Andy Baddeley, who co-founded The Running Channel, which provides advice and tips for runners. "Fast-twitch fibres are more explosive but much quicker to fatigue – more associated with weightlifting and sprinting," he says. "Slow-twitch fibres are slower to recruit, less explosive, but can keep going for a long time without fatiguing."

That means a sprinter can accelerate fast and reach high top speeds, but their body's explosively trained muscles will soon fatigue over longer distances. Baddeley explains this difference using his own running physiology. He reckons that in his Olympian middle-distance days, he could run the 100m in around 11.7 seconds (which incidentally would make for a close race with a gorilla). That's slower than an elite sprinter.

However, he believes he could give an elite sprinter a close race over 500m, and would definitely beat any sprinter – even the world's current fastest – over his specialist distance of 1,500m, because of his body's ability to hold speed for longer.

The same applies to the animal kingdom. The GPS collar study of cheetahs, for example, showed they usually only hold their top speed for a couple of seconds, and a typical hunting run distance was less than 200m (656ft). They're sprinters, not endurance athletes (or at least do not have the inclination or need to run further).

By contrast, pronghorn antelopes – a prey species – have been measured running for 11km in 10 minutes, at an average speed of 65km/h (40mph). As Hirt puts it, recalling an old adage, "For a predator it's your meal, but for the prey it's your life. So the pressure to be quick is much higher on prey than on predators."

Overall, humans are better-suited to long-distance endurance running than sprinting, thanks to our biomechanics, and the fact that we're mostly hairless and we sweat. Some evolutionary biologists speculate these adaptations evolved to help us pursue and tire out prey over many kilometres.

So, could we even get the gold medal in a long-distance race against other animals? It depends.

For one thing, there's not much scientific data to go on. Non-human animals have no desire to push themselves to a personal best in a marathon (26.2 miles or 42.2km). In the lab, it could be unethical to make them do so; in the wild, many would stop or slow long before a finish line.  

For hints, there are scientific databases that have compiled animal "travel speeds": the sustained, aerobic pace animals habitually and comfortably cruise at over longer distances. So for example, while a black bear has a higher top speed than a human, its travel speed is lower, at 2.6km/h (1.6mph). Meanwhile, the tiger's travel speed is 3.5km/h (2.1mph), the dromedary camel's is 6.3km/h (3.9mph), and the grey wolf's is 7.9km/h (4.9mph).

That's slower than the average pace of all runners in the London Marathon, which is around 9km/h or 6mph. And much slower than the world record of 1:59:30, set this year, which was run at an average pace of 21km/h (13mph). However, travel speed is not necessarily the fastest that animals could run long distances – it's more equivalent to human walking. A bear probably could traverse a long distance quicker than its travel speed, but it's difficult to tell definitively whether it would overheat and burn out if it ran a marathon the same speed we do.

Still, despite the gaps in the animal speed data, it's safe to say that humans would not be the best marathon runners in the animal kingdom, despite our endurance adaptations and mental will to run that far.

Husky dogs, for instance, can traverse very long distances at speed. Based on the times they can achieve in marathon-length sled races, they could beat the human world record by more than half an hour. Unladen by weight, they'd likely be faster.

A horse trained for endurance, too, could beat a majority of people over a flat marathon. Although it does depend on the terrain. Every year in Wales there's a human vs horse race over a mountainous route about 22 miles (35km) long. The horse usually wins, but occasionally humans have come first.

It's even less clear where we'd sit in the animal rankings over really long-distances, such as ultramarathons and beyond.

Again, huskies still probably would beat us: the Iditarod Trail Sled Dog Race in Alaska is 1,600km or 1,000 miles. While it's a team race, some dogs run the entire distance, and the course record is seven days and 14 hours. For comparison, the record for the Iditarod Trail Invitational – a similar-length race in Alaskan conditions that some humans complete on foot – is 19 days, 9 hours and 38 minutes.

Still, there probably aren't many animals capable – or indeed willing – to run ultramarathons. In addition to our physiological endurance, the human brain is its own superpower at such distances. Consider the Self-Transcendence 3,100 Mile Race – a 4,989km-long race around a single block in Queens, New York. The current record-holder ran for more than 40 days to complete it (with six-hour breaks at night), at an average pace of roughly 6.9km/h (4.3mph) while moving.

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"Ultimately, long-distance running comes down to: are you comfortable being uncomfortable? Are you suffering?" says Baddeley. "There's still that ability to access another energy system at the end of a long run – to go through the pain and still sprint when the finish line's in sight. I don't know whether you'd see that in the animal world."

Unfortunately, though, that wouldn't help me if I was out for a jog and encountered a particularly grumpy grey squirrel or badger. Could I outrun them if they went for me? Probably not. Unlike bigger animals like elephants, they are both small enough to hit their top speed in a stride or two, and that pace, around 30km/h (18.6mph), is already higher than my sprint. I may have to start training a little harder.

* The animal speeds in this article were mostly drawn from A general scaling law reveals why the largest animals are not the fastest (Hirt at al, 2017) and The body size and temperature dependence of organismal locomotion (Cloyed and Dell, 2020). 

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