<As you get older, you have to invest in your muscles>

<As you get older, you have to invest in your muscles>

1. Skeletal muscle refers to muscles attached to the skeleton and is the body's largest tissue, accounting for about 40% of its weight.

2. It is easy to understand physical activity, that is, an organ used to move or exercise the body, but (skeletal muscles) play a wide variety of other roles. Not only does it maintain body temperature, it also secretes hormones. Skeletal muscles also secrete cytokines and are involved in the immune system.

3. Above all, skeletal muscle plays a very important role in metabolism. Not only does it actively inflow and store glucose, but it also stores some protein in the form of amino acids. Skeletal muscle makes up 50-75% of the body's protein.

4. In addition, skeletal muscle inflows about 70 to 80% of glucose that rises after meals. Therefore, insulin resistance can lead to systemic insulin resistance if blood sugar is not properly managed after meals due to insulin resistance in the skeletal muscle.

5. As skeletal muscle has a great effect on sugar metabolism and energy metabolism, you need to maintain your muscles well in order not to suffer from metabolic abnormalities. The more muscle mass, the better the insulin sensitivity, and the more muscle mass and muscle strength decrease, the more severe the insulin resistance.

6. Most people's skeletal muscles decrease little by little every year after the age of 40. As we get older, mitochondrial function decreases along with decreased muscle mass. Then, oxidative stress (active oxygen) increases and an inflammatory reaction occurs. This causes 'insulin resistance', which damages the signaling pathways of insulin.

7. Fat accumulates in muscle cells when insulin resistance occurs in muscles because fatty acids are not used well as energy sources. Just as fatty liver causes insulin resistance, fat accumulation in muscles also leads to insulin resistance.

8. It may be because of aging that blood sugar levels rise with age and poor sugar control, but decreasing muscle mass also has a significant impact.

9. According to the study, muscle mass decreases by 0.8% every year from the age of 40, and then steeply decreases by 1% every year from the age of 60, and 1.5% from the age of 70.

10. In summary, as we get older, the function of mitochondria decreases, and this decrease in function leads to an increase in free oxygen and fat accumulation in the muscles. This causes insulin resistance, and if the muscle mass decreases, the progression speed becomes faster.

11. The role of skeletal muscle, which has recently attracted attention, is that it also functions as an endocrine organ. (The skeletal muscle also secretes a variety of hormones, unfortunately) All the effects of various hormones must be 'exercised'.

12. Exercise not only activates muscles to release various substances that are beneficial to the body, but also facilitates fat metabolism.

- Park Yong-woo in "My Body Revolution"