You are probably one of those who consumes the correct dose of protein, you sleep well and you do your routine perfectly 6 times a week, but you lose muscle; probably the reason is that you are already over thirty years old.
Sarcopenia, the loss of muscle mass with age, can begin at age 30 and affects a large proportion of the elderly. Fortunately, exercise can combat muscle aging, likely by reversing many of the age-related physiological changes at the root of this decline.
THE REASON WHY YOU LOSE MUSCLE
Muscle stem cells, or satellite cells, decrease in number as we age. In the cells of elderly humans, DNA methylation suppresses the expression of some genes, including sprouty 1, an important regulator of self-renewal in satellite cells.
In addition to stem cell decline, mitochondria also suffer, as muscles develop abnormalities in mitochondrial morphology, number, and function with age.
In addition to the aforementioned, there is also autophagy, old muscles experience lower levels of autophagy. In combination with decreased protein production, this can lead to an imbalance of proteins linked to muscle aging. “As time goes by you start to lose muscle and it is much more difficult to build it, this usually happens in the 40’s” explains Pepe Oliva, nutrition expert and certified trainer.
Signaling factors known as myokines can be released into the blood directly or through excreted vesicles, and travel through the circulatory system to coordinate muscle physiology and repair. For example, apelin, which decreases with age, stimulates the formation of new mitochondria, stimulates protein synthesis and autophagy, and supports the function of muscle stem cells.