What do stem cells have to do with body building? Turns out quite a bit. According to a new paper, mesenchymal stem cells (MSCs) injected into muscles followed by eccentric exercise will make muscle cells more numerous and bigger.
Mesenchymal stem cells and other adult stem cells live throughout your body in nearly every tissue. They are there to act as maintenance men to help repair the small day to day damage that occurs with daily activities. In particular, if you lift weights, muscle stem cells are there to fix the damage that a heavy work out can cause. However, exactly how all of this works isn’t well understood, hence the need for the current research.
The study authors here used a research protocol that would make WADA (the World Anti-doping Agency) cringe. They took mice and either injected MSCs or saline and then either kept the mice lazy or had them perform eccentric exercise. Eccentric lifting is also known as “negatives” or when you focus more on letting down a heavy weight (an eccentric contraction) than lifting it up (a concentric contraction).
The results? The mice who got stem cells plus eccentric exercise had far more and far bigger muscle fibers than those who got saline or got stem cells plus no activity. For the study authors this meant that the body likely brings MSCs to the area after eccentric exercise to help the local muscle stem cells work better. However, there’s another possible message here that begs to be discussed-stem cell doping.
MSCs from bone marrow or fat are easily obtained, isolated, or grown to bigger numbers. They can be saved for future use via freezing. They would also be completely undetectable using current chemical based drug tests. In fact, it would take some sophistication to design a muscle biopsy test to detect this type of doping and if the cells were your own, doping may be undetectable with any certainty.
The upshot? Will we see stem cell doping in body building or sports? I expect we will, for no other reason than this type of nefarious activity will be almost invisible to detection.