Toxins can definitely be found in muscles. Specifically, for example, lead can be found latched on to individual muscle cell membranes through its affinity for calcium-activated potassium channels.
Many other things, mostly naturally found toxins, can also be in muscle – things like tetrodotoxin from the puffer fish, some scorpion venoms, and nicotine. Man-made drugs, too, like phenytoin that is used to treat seizures, can get stuck there for bit.
When it comes to stuff most people worry about with detox, things like pesticides, there is also some evidence that DDT and pyrethroids can latch onto muscle cells. For the most part, however, the nastiest stuff like that goes to our fat cells.
Most muscles have fat cells around them. The fat is used as energy as the muscles run out of more readily available sources. Burning the fat helps to release environmental chemicals stored there.
Does stretching help to detox the muscle and to get rid of these toxins? Sure. All movements require “work” of a muscle. Stretching one generally means the contraction of another. Both help to bring new blood flow to the area. It’s the blood flowing through a muscle tissue that helps to “wash away” toxins that are hanging out there, lowering their concentrations. The more blood flowing through an area, the better the flush.
“I also hear that stretching in asana will get into areas of the body that are seldom moved, and will remove toxins lodged in these ‘little nooks and crannies’ of our bodies.”
That’s a cute way to promote the asana, but all “little nooks and crannies” of our bodies get blood flow or the cells would die. They get blood flow whether they “move” or not. More movement brings more blood flow for nourishment and removal of toxins.
As for sweating, it is definitely one mode of elimination of some toxins – but only those of a certain chemical nature. And it is a very minor route of elimination.
theYogadr.com