As many faithful gym-goers, as well as those of us who insist on always using the stairs, would say: if you don’t use it, you lose it. Right?
Well, new studies led by scientists from Hiroshima University and Hokkaido University in Japan may point to a way to ensure our muscles retain their mass, even without pumping any iron or pushing through any squats. Their secret weapon? Bear serum.
Bears hibernate during colder seasons for months on end. These seasonal naps can last up to seven months! To prepare for these extremely long periods of stillness, bears will feast with abandon in the summer and autumn to build up fat stores that supply their bodies while they fast over a long inactive winter.
When they finally wake up, bears are pretty much just as strong as when they first laid their furry heads to rest.
Humans, on the other hand, begin losing muscle mass within a few weeks of inactivity. In addition, our muscles atrophy quickly if we stop eating and/or drinking. Without movement or added food, in time all the human body will have wasted away.
Infusing muscles with bear serum
Inspired by the bear’s ability to maintain muscle mass without doing much at all, the scientists decided to investigate further in hopes of figuring out if this phenomenon could be harnessed to enhance human strength and overall health.
The study zeros in on skeletal muscle, which is prone to degradation in the face of immobility. The team took cultured human skeletal muscle cells and infused them with serum taken from the blood of hibernating black bears.
The experiment results showed remarkable protein growth after a period of 24 hours. This sample was compared with serum collected during the bears’ active summer season, which failed to induce the same effects.
The scientists attribute bears’ ability to not use it and not lose it (in terms of muscle mass) to the suppression of a protein called MuRF1 that activates the shredding of inactive muscles. The team is still working on identifying the hormones and pathways that suppress this protein.
“We have indicated that ‘some factor’ present in hibernating bear serum may regulate protein metabolism in cultured human skeletal muscle cells and contribute to the maintenance of muscle mass,” explains the study’s first author Mitsunori Miyazaki. “However, the identification of this ‘factor’ has not yet been achieved.”
Once the factor is identified, it could lead to some impressive rehabilitation solutions: it could potentially protect human bodies during deep space travel or prevent muscle atrophy in those who are rendered immobile by diseases or aging.
Other animal-inspired solutions
If you enjoyed this article and are curious about other solutions inspired by the incredible hibernating animals we share this planet with, we have some other suggestions for you to dive into.
Here’s one that we wrote about the hibernating yellow-bellied marmots’ unbelievable ability to stop aging during hibernation. With further research, this discovery could teach us how to improve human longevity, even though humans cannot naturally hibernate.
If you’re still hungry for more on this topic, check out this article about how animal evolution can help boost women’s health, and how hibernation in particular could lead to effective treatments for osteoporosis.