Many of us have already packed in our New Year fitness resolutions, but these animals keep at it all year round
For humans, exercising can be for a host of reasons, from trying to shift those Christmas pounds to toning up. However, while exercising is recommended for a healthy lifestyle, many people get by with little or no exercise at all. But this is not a luxury many of our friends in the wild can afford. While they may not ‘exercise’ like we do, body conditioning is imperative for many animals.
Fun running rodents
Watching a hamster using a running wheel doesn’t seem like something that offers much scope for scientific investigation, but that couldn’t be further from the truth. These furry little mammals, along with mice and rats, seem to derive a ‘runner’s high’ from exercise, just like we humans do.
Studies have found that 30 minutes of running increases dopamine metabolism in mice. A regular run has also been shown to induce angiogenesis (the formation of new blood vessels), as well as an increase in fitness levels. But perhaps most interestingly of all is that running has a physical impact on a rodent’s brain.
Wheel running has been found to increase growth factor expression and neurogenesis (the formation of new neurons) within the hippocampus region of rodents’ brains. In rats this development is linked to an improved ability to learn a conditioning task, therefore proving that this form of exercise can provide rats with a neurological advantage.
However, it’s not just captive animals that will hop on a wheel. Wild mice, rats and even frogs have been examined using them without any encouragement, meaning that regardless of their surroundings, a variety of animals will gladly go for a run.
Life in the ocean can be incredibly tough. Ranging from predators to pollution to epic migrations, it’s an existence wrought with danger and hardship for many animals, and when it comes to mammoth journeys, few undertake anything like the humpback whale.
Travelling further than any other mammal, these graceful leviathans swim phenomenal distances, with the longest recorded migration clocking up 18,840 kilometres (11,706 miles) from American Samoa to the Atlantic Peninsula. No mean feat for an adult humpback, so how on Earth do the youngsters get in shape for such a swim?
Humpback calves are often spotted breaching the surface of the water in what appears to be a rather energy-sapping exercise. However, a study conducted by researchers at the California State University Channel Islands has found that this playful splashing about serves an important purpose: it helps the young whales to build up their reserves of myoglobin, a protein that enables them to remain underwater for longer.
While adult humpbacks can remain under the surface for up to half an hour at a time, their babies have to come up for air every 30 seconds or so. However, by exercising their muscles the calves release calcium into their muscle cells, which in turn leads to the production of myoglobin. By tripling the amount of this protein in their muscles, calves can swim more efficiently underwater for longer.
A life-saving diet
It’s common knowledge that being overweight can lead to a host of ailments including heart disease, diabetes and some types of cancer. However, while it’s in our interests to stay trim in order to avoid these diseases, we don’t need to watch our weight quite as obsessively as some animals. For some creatures it’s a case of skip lunch or become lunch, and it’s a delicate trade-off thought to be dictated by an animal’s mass- dependent predation risk (MDPR).
This theory posits that while an animal storing fat reserves decreases its chances of starvation, its increase in mass as a result of this storage can result in making the animal slower and therefore less able to evade a predator. A bigger mass also enhances an animal’s exposure, as it will need to find more food in order to sustain its newfound weight.
A prime example of this is the harbour porpoise. Found in the cold waters of the Northern Hemisphere, these shy predators often find themselves hunted down by bottlenose dolphins, which will kill a porpoise but will not eat it. A study in 2007 conducted along parts of the UK coastline found that in areas where there was an increase in dolphin predation the porpoises present were carrying a lot less energy reserves than normal, significantly limiting the length of time that they could last between feeding.
This experiment seemed to suggest that the porpoises were willing to cut down on food if it meant they stood a better chance
of evading a murderous bottlenose. It also debunked the theory that this balancing act only applies to birds, which have also been recorded shedding weight to avoid predators.
Words: Charlie Ginger