Do Weight Lifters have Better Muscle Stem Cells?
There are stem cells literally all over our bodies. This topic of stem cells being in many tissues is discussed in more detail in our medical practice’s book, Orthopedics 2.0. They also live in our muscles and they helps to make our muscles bigger and stronger as we lift heavy weights. This happens through “differentiation”, where these master cells become muscle cells when called into action by more demand on the muscle. Being a middle aged weight lifter, I was fascinated a few years ago by a study of heavy weight lifting in elderly patients. First, what do I mean by heavy weight lifting? This type of lifting is different than just performing a couple of reps under the muscle is sore. Instead, this means lifting a weight that feels heavy until the muscle fails at usually 6-10 repetitions. The study I’m referring to used this method and demonstrated that the muscles of elderly weight lifters were more similar at a genetic level to the muscles of younger people then their elderly counterparts. What was interesting is that the heavy weight lifting changed these muscle cells and reversed many of the problematic genetics and cellular problems seen in the muscles of elderly patients. A 1990 study found the same thing. When elderly weight lifters were compared to swimmers and runners, the weight lifters had better strength, speed, and muscle composition. In fact, their muscle composition looked more like younger subjects. What other evidence is out there that hitting the weights hard might be good for your muscles and their stem cells? Are muscle stem cells even able to be activated in older patients? The answer appears to be yes, according to a study of elderly men undergoing a 12 week resistance training program. This study showed that the stem cells in their muscle tissue were still capable of proliferation and differentiation (growing more of themselves and turning from stem cells into muscle), which is what made their muscles bigger. The upshot? If you want your muscles to look, feel, and act like the muscles of a younger person, hitting the gym hard may be the answer. Of interest, old muscle stem cells appear to “still have it” despite their age.