If animals start hunting humans, then the sled dogs represented by Erha are the only animals that can kill humans by body, just like humans hunted animals in the first place. Today we will take a look at this kind of stupid goods that hide extremely strong strength.
Siberian husky. Image source: wikimedia
The endurance of humans (at least ancestors) is not to be said, and it is also because of this that humans can "consume" prey that is fast, but cannot run far. However, there is one animal whose endurance is far superior to that of humans, and it is a sled dog.
The most common sled dog today is the Alaskan husky. The strongest endurance player on the surface is the sled dog represented by the husky, and there is no one.
If you don't believe me, let's take a look at this knowledge point first: the world's toughest endurance race isn't a human triathlon, but an Iditarod Trail Sled Dog Race.
A team that competed in the Editarod dog sledding competition in 2007. Image source: wikipedia
In 9 days, the dog has to run 1770 kilometers, which is equivalent to 42 full horses. And the journey is not friendly at all, the temperature can be as low as minus 40 degrees Celsius, and there will be strong winds along the way. This is equivalent to braving the siberian cold, pulling a sled, running at least 4 full horses a day in high winds, running 10-12 hours a day, running for 9 consecutive days.
Mike Davis, a veterinarian at Oklahoma State University, says no other animal has the physical abilities of a sled dog.
How did Erha do it? This is all because of their unique fat utilization mechanisms and body repair capabilities that are not yet fully understood by humans.
Like all mammals, dogs can use glycogen in their muscles as fuel when running.
Glycogen is an explosive energy source that is easily utilized by muscles, but is consumed quickly. For most mammals, glycogen is the bottleneck of endurance because mammals have small glycogen reserves that are quickly depleted.
Endurance sports such as long-distance running rely on another energy source – fatty acids. While fatty acids can provide longer-lasting power, they have a problem with being difficult to use by muscles.
This is because fatty acids are insoluble in water, and hemoglobin in the blood cannot carry fatty acids. To transport fatty acids to the muscles to burn, a special intermediary is needed – albumin. In other words, the amount and efficiency of albumin in the blood determines the amount of fatty acids that muscles can use, which determines endurance.
Albumin in the blood of cattle. Image source: wikimedia
Human endurance athletes rely on fatty acids for energy, and their bodies are able to efficiently transport fatty acids to muscles. But compared to dogs, the ability of humans to invoke fat is not worth mentioning. In fact, dogs, including sled dogs, produce twice as much fat as humans.
In 2005, the above-mentioned Davis and colleagues found that, unlike most mammals, sled dogs can quickly use fat instead of sugar to power muscle. However, humans only know a little bit about how sled dogs do it.
For example, the concentration of fatty acids in the blood of ordinary dogs is much higher than that of goats, and the degree of binding of fatty acids and albumin is 50% higher than that of goats, but the amount of albumin in their blood is similar to that of goats.
In addition, sled dogs take advantage of an unknown highly efficient transporter albumin, because the fatty acid transporter albumin in humans is not high in dogs.
Image source: pxhere
This strong fat metabolism ability makes Erha a dog power engine.
The metabolic rate of Erha in the competition is 12.2 times that of the basal metabolic rate (BMR). You know, the highest record of human beings is only 4.3 times, which is still won by athletes participating in the Tour de France, and the average person is even lower.
Tour de France. Image source: wikimedia
This super ability to burn fat also makes Erha a veritable foodie.
When the sled dogs participate in the Editarode dog sled race, the energy intake is about 12,000 kcal per day. And due to the unique fat metabolism, 60%-70% of the sled dog's food is fat when playing a game.
What is the concept of 1.2 million kcal? That's the equivalent of 24 Golden Arches Big Macs. Michael Phelps, a swimmer with 28 Olympic medals, can eat food containing 10,000-12,000 kcal a day while training, and the average person consumes about 2,000-3,000 kcal a day.
Most of the dog food used in sled racing is fat. Image source: iditarod.com
The erha who played the game weighed only about 30 kilograms, about half of that of humans, but they could eat 6 servings of food a day, and most of them were fat oil, which showed how amazing their energy consumption per unit weight was!
When not exercising, these sled dogs can adjust their energy consumption to one-fifth of the time of the race.
The daily calorie consumption (DEE) of a sled dog that does not race is only 2510 calories, which is about the equivalent of an adult man. In fact, in reality, Arctic Inuit sled dogs are only fed in the winter, and they are chained up in the summer to eat a meal for 3-4 days. Therefore, the weight of arctic erha in summer will be about 30% lighter than in winter. Erha's extremely large metabolic range may be an important reason why humans domesticate them in extreme environments.
What's even more breathtaking about sled dogs is their ability to repair.
Human marathon runners need a long repair time after running a full horse, but Erha can throw a second full horse faster than humans.
David said many of the dogs participating in the 2012 Edittarod Dog Sled Race had just participated in the Yukon Quest bobsleigh race three weeks earlier (about 1,600 kilometers). This is hard to imagine if it were placed on humans.
Sled dogs. Image source: wikimedia
He also discovered at the somatic level that humans are inferior to dogs.
After the first few kilometers of running, both humans and dogs can have muscle damage, marked by the protein in the muscle seeping out of the cells. It takes humans about 1 day to recover, and the muscles will still be damaged in the second long run and need to be repaired again.
Sled dogs are different, when they run two brushes, there is no protein in their muscle cells that seeps out, indicating that their muscle cells will not be repeatedly damaged. After the 4-day sled race, the dog's metabolic activity is the same as it was at the beginning.
In 2007, Erica Mckenzie, a professor of veterinary medicine at Oregon State University, and colleagues found something similar: After five consecutive days of 160-kilometer races, the biochemical index of sled dog blood changed only slightly.
What's even weirder is that the dog who played the second game performed even better than the first time. David says, "The best warm-up for a sled dog is a 1600k race. They can race all the time, as long as there is plenty of food. ”
Obviously, for such an athlete beyond human imagination, ordinary walking is certainly not enough, which is also an important reason why sled dogs are easy to give up: their range of motion is based on the whole horse, how many miles is your community?
Therefore, only Erha can consume people to death. But Erha did not choose to do this, just ran a cool demolition home, which shows how deep its love for human beings is!
Cover source: wikimedia
Resources:
https://docs.qq.com/doc/DVFVEaWtpUFZGaFl5
Written by Seven Kings
The reproduced content represents the views of the author only
Does not represent the position of the Institute of Physics, Chinese Academy of Sciences
If you need to reprint, please contact the original public account
Source: Bring science home
EDIT: Hidden Idiot
![The 6 benefits of singing are closely related to longevity? Long sighted![fig]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)