How does the heat make muscles pliable?

I have a question, and I appreciate the opportunity to ask. I appreciate all forthcoming answers that people believe to be true, and at the same time I have high hopes that my question is viewed by eyes that have looked through many books during their time in medical school 🙂

We know that when “working out” peoples bodies “loosen up”. Joints get warm, muscles get pliable, and people sweat. We know that in a Bikram class this “process” is amplified, and often enough Bikram Teachers say to students words to that effect.

The question is: what — exactly — is happening on a cellular level?

As it relates to joints: heat makes the “fluid” between bones become more viscous. “heat” will “warm things up” (as well as “make them move faster”), and since we know that water expands under conditions of heat, understanding the “heats effects on joints” is somewhat straightforward.

What I am trying to wrap my brain around is what — exactly — is happening with muscles. I can imagine that heat would make the water within each cell expand. As the body works, the body’s muscles systems are rearranged, and the individual cells are treated like sponges (what we may call “detoxification”). But what happens if we zoom out from the cell and look at the entire muscle. Why — exactly — is the heat making it more pliable? Is it related to the enhanced water “movement” already described? Does it have anything to do with heat possibly having an effect on the cell walls themselves, allowing them to “loosen up”? Or, if we zoom out again to look at the whole muscle (and maybe higher to a “group of muscles”) then could it be that heat makes the fascia “loosen up”?

And so this is the question that I have. How — exactly — does heat make the muscles more “pliable” in real time?

• This topic was modified 2 years, 8 months ago by TravelingAsana.