- Ever wondered exactly how muscles adapt as we get fitter?
- We know the more we exercise, the fitter we get, but what exactly are the mechanisms?
- According to new research, it's an enzyme that primes fat cells to aid muscles
There is only one way to get fit – more exercise. Not only does exercise help us maintain a healthy weight, but it also enhances insulin sensitivity and improves our metabolism to help us become fitter and stronger.
Even though we know this, the biological mechanisms behind fitness aren't fully understood. Now, new research published in the journal PNAS suggests that it can be explained by the way skeletal muscles and fat tissue communicate with each other.
An enzyme primes fat to help muscles
The researchers from the University of Copenhagen and the University of Campinas performed experiments on both mice and humans and found that short-term exercise training increased levels of a certain enzyme in fat cells called DICER. This DICER enzyme in fat assists muscles to adapt to exercise and increases performance as it primes fat cells to release fatty acids that muscles need into the bloodstream.
The scientists stated that DICER works by regulating a microRNA molecule that stops fat from utilising glucose from the bloodstream.
In their study, they show that mice that are unable to produce the DICER enzyme do not get fitter from exercising – but when blood from previously exercised mice are transferred into non-exercised mice, the level of DICER levels are increased in the non-exercised mice. According to the researchers, this suggests that exercise training causes muscles to release a molecule that causes fat cells to produce more DICER.
Not a new idea
Associate Professor Jonas Treebak said in a news release: "The idea that skeletal muscle signals to other tissues in response to exercise is not new, and although the specific signal from muscle remains elusive, we have identified a signalling axis between muscle and fat that is central for the adaptive response in muscle to exercise training."
He adds: "The next steps are obviously to identify the circulating factor from skeletal muscle as well as to identify the target(s) of the specific microRNA."
Image credit: iStock