A Workout Without Working (Much)
Feel like you just ran a mile after walking a block? Do your muscles feel tight and contracted? How’s your flexibility and coordination? If I’m reading this right this fibromyalgia study might be able to help explain why these problems are occurring.
We recently saw a study which suggested that something as simple as mental stress tests (math test) or eating or other sympathetic nervous system activators can activate the back muscles of people with fibromyalgia. That study suggested FM patients muscles could be in state of almost continual activation.
Now we look at the muscles of people with fibromyalgia under load; that is. when they’re being exercised….and find that much the same thing is occurring – only magnified.
In this study people with fibromyalgia and health controls carried weights in their hand and then flexed their arms back and forth for 3-5 minutes while researchers measured the electrical activity using in their biceps.
Endurance – Normal; Everything else – Abbey- normal.
The study found that endurance in this short muscle test was normal but virtually every other test result was abnormal in the FM patients.
Wired and Tired Muscles as Well…
One might have thought that strength and frequency of the electrical signals would have been reduced in these exertion challenged FM patients but as so often happens, the opposite was true; the electrical signals in their muscles were, oddly enough, going banana’s, putting them were into a hyper-active state.
Electrical signals trigger the muscle contractions we use to produce force but those signals should diminish in between the muscle contractions. They did in the healthy controls but not in the FM patients whose muscles were being constantly prodded to contract.
This didn’t mean they were supermen or women in disguise; far from it – the inability to turn their muscle activity off and allow them to rest – suggested their muscles were chronically tensed, not strong. (Shades of the wired but tired problem in ME/CFS).
“It has been demonstrated that patients with FM have sustained muscle activity between contractions, that is, they are unable to relax..”
Several things can cause this kind of unremitting electrical activity but in this case it appeared that alterations in the ‘muscle fiber membrane’ or ‘ sarcolemma’ were responsible. Unusual in cellular membranes which generally prefer to stay on the surface of the cell, the sarcolemma dives deep into the big muscle fiber cells where it transfers electric signal that tells them to contract. The muscle fiber membrane , then, plays a key role in energy production.
Muscle ‘Arrythmias’ Anyone?
The authors believe this continued state of activation left the muscles in a state of something called ‘afterdepolarization’. Depolarization simply refers to a change in the electrical status of a membrane. If I have this right, the membrane should switch from positive to negative regularly – allowing electrical currents (ions) to contract, relax, contract, relax, etc. the muscles. In a state of depolarization a state of confusion reigns interrupting that regular pattern of ‘depolarization’, leaving the membranes in a twitchy, unsettled state. In heart muscle afterdepolarization can cause tachycardia or arrythmias.
It just so happens that afterdepolarization causes he muscle membrane to send the ‘contract’ message more easily. What’s causing this state of affairs? The authors didn’t say but depolarization is a function of ion channel (Ca, K, Na, CL) activity and the autonomic nervous system may be involved as well.
Because the tests were done in muscle areas that did not have tender points they believed this pattern applies bodywide.
With your muscles in a continually contracted state every time you put them under load it may be that you are running a marathon for every mile you walk. This study suggests that exercise may throw the muscles of people with FM in a state of confusion in which muscle rest breaks disappear leaving the muscles chronically activated (and in an arrythmic state?). Given the worsened exertional problems in ME/CFS, it’s possible the same or worse applies in that disorder.
The ongoing sympathetic nervous system activation, the possibly increased glutamate activity, the NK cell burnout, the inability to turn off attention to innocuous stimuli and now the ongoing electrical activity/muscle contraction in FM all suggest chronically activated systems play a role in this disorder.
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