From: “Why Muscle Matters & How to Build it” on “Perform with Dr. Andy Galpin” podcast.
In his new podcast, Galpin, one of our go-to experts on muscle and strength, describes the critical role of skeletal muscle, i.e. muscle that controls our movement. I love his emphasis that skeletal muscle is very adaptive -> we have a lot of control over it!
Interestingly, it was only recently discovered that skeletal muscle is an organ, meaning it not only receives signals, but also sends signals to communicate with the rest of the body. For example, in response to exercise, muscles secrete "exokines" that communicate with the brain to support cognitive function and improved mood.
Skeletal muscle plays a huge role in metabolism. It is the primary site of glucose disposal and regulation, important for both performance and long-term health. Galpin cites research showing that “athletes are up to 25% more effective at disposing glucose into muscle than non athletes.” You don't have to be an athlete to benefit, by simply moving frequently, you activate your muscles, which helps to regulate blood glucose and reduce your reliance on insulin (a very good thing!)
Muscle fiber type has important implications for aging. Skeletal muscle fibers consist of Type 1 (“slow twitch,” for endurance), and Type 2 (“fast twitch,” for speed and power). Your proportion of fast vs. slow twitch muscle is very responsive to training. You tend to retain more slow twitch muscle as you age, because you’re constantly engaging it in daily activity (e.g., standing, walking) However, you only activate fast twitch muscles with a lot of force. You need strength training and power movements to maintain fast twitch muscle, or you will lose it!
Does it matter if you lose fast twitch muscle? YES!! You need fast twitch muscle to generate power - e.g., to catch yourself from a fall, to catch a train, to run from danger. When you lose it, you not only diminish your ability to generate force, but you also lose motor control. And once you lose this muscle, it’s very hard to get back.
Galpin reminds us that muscle mass is not necessarily indicative of muscle strength and vice versa. Muscle strength tends to be more predictive of healthspan and longevity than muscle mass. He notes that in addition to weightlifting, good ways to measure and track muscle strength include grip strength, vertical jump, and broad jump tests.
