Of the many downsides to being a human being—as opposed to, say, a squirrel, or some kind of fantastically plumed bird—exercise is one of the more egregious. Awareness of mortality is bad enough—do we really have to jog, on top of that? Still, animals are like us in so many ways that it’s worth wondering whether they subject themselves to this bizarre ritual as well. For this week’s Giz Asks, we reached out to a number of animal behaviour experts to find out.
Assistant Professor of Psychology and Principal Investigator of the Human-Animal Wellness Collaboratory (HAWC) at Monmouth University
Whether animals “work out” is a question that has only just been posed in recent years by scientists. If we are simply defining “working out” as engaging in physical activity that increases an individual’s fitness, then yes, animals definitely do this. Many animal species—by engaging in certain species-typical behaviours—can signal to a potential mate their fitness and ability to produce viable offspring. There is also much evidence in behavioural ecology research that animals adjust their food intake based on whether there is high predation risk.
But do animals have the same intentions as we do when we work out? The question about whether the individual engages in activity specifically for the purpose of preparing for “high stakes” events, like evading a predator or showing off to a mate, is more difficult to test scientifically. Whether the individual animal is aware of the evolutionary consequences or lifetime benefits of these active behaviours is another empirical question we can ask. But regardless, it is clear that there is at least a correlation between activity and fitness or reproductive success.
That being said, we have reason to believe that engaging in these sorts of behaviours often just “feels good” and are reinforcing to an animal. Similarly, working out can feel good to us (well, most of the time anyway).
There’s even some recent theories and scientific data out there to suggest that the pacing seen in zoo animals might correlate to welfare in a less than obvious way. There are many hypotheses about why animals pace. Though often associated with boredom or stress (and thus, negative welfare), it’s been suggested that species that have naturally large home ranges (like tigers, bears, and wolves) may actually be pacing in order to adapt to life in captivity and to ensure they are still getting the exercise in a relatively smaller space. So, it’s important to keep in mind that sometimes “working out” may not look like what we expect it to!
The value of physical activity to an animal is also seen in the fact that lethargic behaviour or lower levels of diversity of species-typical behaviours overall is typically a cause for concern. Certainly, some species may not appear to need as much activity as much as others (consider relatively slow-metabolizing species like Galapagos tortoises, African lions that naturally sleep on average 16 hours each day, or bullfrogs who are ambush predators and owe much of their adaptive success in catching prey to being able to sit still and wait for long periods of time). So, while we just need to keep in mind that what constitutes a “lethargic” animal depends on the species we are talking about, a lack of activity levels below what is normal for that species overall is something we can often interpret as being a concern.
So, do animals “work out”? We certainly need more research on the matter; it’s a topic worth exploring. While the answer likely depends on the individual animal and what opportunities their environment affords, but it is clear that, just like us, engaging in physical activity and species-typical behaviours—whatever your species—is important to maintaining good animal physical and psychological health and welfare.
Professor and Board of Governors Research Chair, Neuroscience, University of Lethbridge
At younger stages of life, especially in the juvenile period (the age between becoming independent feeders and becoming sexually mature), many animals engage in excess behaviour, often recognised as play. Among other things, such play provides the opportunity to get fitter and improve motor coordination (this has been shown in several species of mammals, including humans).
Such playful activity diminishes with age, when fully independent. Typically, adult animals gain their exercise from their day-to-day activities, mostly in their foraging activities. We get a sense of this from captive animals in two ways.
First, consider large captive carnivores (most strikingly seen in polar bears), which spend a lot of their day walking back and forth in their cages. The larger the home range traversed daily in the wild, the more intense these stereotypic movements (hence the exaggerated pacing in captive polar bears).
Second, consider a mouse or hamster in a cage, with food and water freely available. It could just sit there and eat when it wants, but put a running wheel in the cage and it will run incessantly for hours at a time.
Both cases show that animals maintain their mental and physical health by some amount of daily exercise, and when this is missing from the daily routine provided by living in the wild, animals will compensate to achieve that level of activity.
In some cases, even in the wild, animals will engage in activities that may maintain their prowess in important activities such as foraging skills. For example, adult long-tailed macaques engage in stone handling that simulates the actions they perform when foraging (e.g., breaking into nuts). This may help maintain their skilled actions and provide therapeutic stress relief.
So, the bottom-line is that while exercise in animals hasn’t been directly studied, there is considerable circumstantial evidence that some species can supplement their activity level to maintain them in peak physical and mental health.
Professor, Ecology and Evolutionary Biology, University of California Los Angeles
Many species of animals play and play works out both the muscles and mind. If you’ve ever been to a dog park you know that dogs play, but so do many other wild species. In many species, play is restricted to young animals. In predators, play provides necessary practice for later hunting, and in prey, play provides a safe place to learn to escape. Play also provides a low cost way to sort out later dominance relationships—as I’ve shown in my studies of yellow-bellied marmots. What’s fascinating is that play fighting clearly isn’t real fighting—animals switch roles of dominant and subordinate and in many species, like dogs and their relatives, there are specific play faces and signals that have evolved to ensure that everyone knows that the rough behaviour is really play. Some species play with objects to improve later manipulation skills. And studies of rodents shows that those that play more have greater brain development. Play is so important for normal development that it takes a lot to deprive an animal of play and play deprived animals are a mess. Play looks fun, and likely is fun for those playing.
Professor, Zoology, Harvard University
The best examples I know of this phenomenon come from young birds and mammals. They don’t exercise or practice to get in shape as much as to develop and hone complex behaviours that are critical for survival. Fledgling birds, for example, can be pretty clumsy fliers during their first few attempts but typically get better each time they try. Likewise, juvenile carnivores, e.g., young lions, will “practice” catching prey even though their still being fed primarily by their parents.
Professor Emeritus, Behavioural Ecology, Mt. St. Vincent University, whose primary study species are wolves, coyotes, caribou and black bears
Do animals intentionally “work out”? Of course: it’s called life. Whatever members of a species typically do to survive and reproduce should be sufficient to keep them physically fit, without the necessity to set aside time and energy over and above what they expend just getting through their day. Natural selection has shaped their bodies, their physiology, and their behaviour for whatever they must do, whether it’s capturing prey, avoiding becoming a meal, competing for a mate, protecting young, and so on. A wolf might travel 10 to 20 kilometers or more during a day, searching for and perhaps chasing several prey, and even if unsuccessful, it’s better to spend its time actively hunting rather than doing laps or interval training with no prospect of payoff.
Of course, that’s not to say that experience is not without its benefits, and early experience for a lot of species involves play. Wolf pups stalk, ambush, chase, pounce and wrestle as they play-fight with their litter mates. Although one can argue that these various behaviours are innate, simply part of the genetic disposition that makes wolves wolves, most complex behaviour patterns benefit from practice. In this way, the crude and clumsy actions of pups give way to the more refined and economical behaviour of adults. Thus in one sense, play can be viewed as a “workout” that leads to better fighting and hunting skills. But those outcomes are not the intentions of the pups. They simply intend to have fun.
On that note, if we switch to the human animal, we find a species in which play plays a dominant role in everyday life, especially for kids, and although play does lead to the honing of a variety of physical (and mental) skills, it’s the prospect of having fun that keeps both kids and adults playing. Take away the fun, and we soon stop. Our hunter-gatherer ancestors likely had little need for the “work out.” Their daily activities kept them strong enough, fast enough, quick enough and smart enough to get through life. Play as children helped hone the skills needed as adults, and using those skills as adults kept them sharp. And using those skills, whether it be tracking, pursuit, spearing, etc., was likely never viewed as “work.” It was fun. “Work” and the “workout” were later inventions.
Graduate Student, Animal Behaviour, UC Davis, whose research focuses on social behaviour in primates, among other things
In my time watching lemurs (primates from Madagascar) in the wild, I’ve never seen anyone “exercising” as humans would. Everyday, wild animals spend the vast majority of their day trying to find enough food and avoid getting eaten by their predators, so there is not much time to engage in exercise like humans do.
While they may not work out intentionally, they do have ways to gain skills—both physical skills but also mental and emotional coping skills. In fact, one of the main hypothesized reasons that animals play is to gain these skills, to allow them to deal with unexpected circumstances—things like chasing down a prey animal or fighting with another animal. We have found consistent support for this hypothesis in a variety of primate species from all over the world, including capuchin monkeys, hamadryas baboons, and diademed sifaka. While most of this play is when animals are young, we’ve noticed many of the sifaka that we study continuing to play into their adult lives. In early life, a lot of their play is jumping, running, and moving around, so may provide a lot of physical training. In their adult life, almost all of the play we observe is social, which serves to “exercise” their social skills and relationships.