Sharp pain as soon as muscles lengthen?

[derzwerg]

For a few weeks now I've been having this sharp "tearing" kinda pain in multiple muscles. It's the worst in my quads. I can feel it in the medialis, lateralis, femoris in both legs. Where I feel it varies depending on exactly how I'm moving. But this also happens in my triceps, biceps, and forearms. By far the worst in my legs though.

It doesn't matter if it's loaded or not, as soon as my knee starts to bend I get very sharp pain. Almost like the muscle feels the stretch and is contracting in response. This happens like going down stairs but also if I'm bringing my knees toward my chest to put socks on or something.

I have a job where I'm on my feet and up and down a lot and I've found that on days off, when I'm more sedentary, this happens much less frequently.

I tried a week off training and didn't notice any meaningful improvement. My legs actually feel better immediately after training and even into the next day. Stretching will alleviate this but only briefly. I can usually avoid it by doing things very slowly. So if I have to bend my knees to take a seat, going down real slow will usually prevent it.

So. Any thoughts on what's going on here? For whatever it's worth, ChatGPT says something along the lines of neuromuscular hyperexcitability... More or less the muscle spindle is overreacting to the stretch and contracting the muscle to prevent tearing. Chat also blames this on recent illness, elevated sympathetic tone, and increased neural drive due to some superdrol lol.

This did begin after a couple weeks of using superdrol pre workout and I did get sick shortly after this started.

I appreciate any insight. I feel this will likely resolve on its own, in time, but I am curious what's actually going on here and if anyone else has dealt with something similar.

 

[killinit8]

Generic question im sure. How's your hydration? Not just water

 

[derzwerg]

My hydration was unchanged when this began. At that time I was drinking 5-6 liters of water per day with 1.2g sodium, 1.5g potassium. 800mg elemental magnesium and 5-10g taurine per day.

I've played with electrolytes a bit but it hasn't made any difference and it doesn't feel like that sort of electrolyte imbalance cramp.

I've since stopped adding sodium and potassium and don't notice much difference aside from maybe the pumps aren't as great. Still good but definitely better when I was adding na/k through the day.

The issue persists. I've added in glycine and agmatine before bed, as per Dr. GPT's recommendation. Maybe it's helped a bit idk.

It's also worth mentioning that my T3 was below the normal range and Dr. GPT believes that is the root cause.

"Low T3 increases motor neuron excitability and reduces spinal inhibitory tone. This raises gamma motor neuron gain, making muscle spindles hypersensitive to stretch. When a muscle begins to lengthen, the spindle overfires and triggers an inappropriate stretch reflex—causing a brief involuntary contraction during eccentric movement. That contraction against lengthening produces sharp, tearing-type pain and post-movement twitching, without true weakness or structural injury."

My iron panel was also off. Iron and ferritin were both in range but saturation was low and binding capacity was high, which looks like an iron deficiency. T3 was at 55ng.

Since iron is involved in t4 to t3 conversion, I'm hoping correcting the iron will bring the t3 in range and resolve this issue.

I've been supplementing iron for five weeks and I just got another sample taken this morning so we'll see if iron or t3 have improved soon.

 

[TheOtherOne55]

Did this start out of nowhere? Any recent weight gain? Or cut? To me, it sounds like an electrolyte imbalance but if you’ve been the same weight then I’m unsure how it would pop out of nowhere.

 

[stackdizzy]

If it started when you started taking superdrol your prolly just not taking enough and need to triple the dose at least. Seriously though this could be a lot of things. If it started when you started superdrol, try something else or maybe come off orals for awhile and see what happens. Id give this about another 1-2 weeks and if it was still there I'd go talk to a doc.

 

[qbkilla]

Probably one of those things that just goes away. Id try a month of carnivore if it were me. Horrible diet long term but its an elimination diet too could give you a nice reset reduce inflammation without needing deugs

 

[Fa Seeshus]

Taurine may help. Also is your blood calcium elevated? Hypercalcemia has some of these symptoms. You can get it if you drive down estro too low.

 

[derzwerg]

Did this start out of nowhere? Any recent weight gain? Or cut? To me, it sounds like an electrolyte imbalance but if you’ve been the same weight then I’m unsure how it would pop out of nowhere.

Pretty much out of nowhere. The only thing that changed was the superdrol, which I've since dropped. I did have a huge swing in weight after a poorly planned cut for a vacation but that was like five weeks before this started.

I'm not ruling out electrolytes but nothing I've tried has made a difference and it really doesn't feel like that kinda cramp. Like I've had clen cramps and this is very different.

If it started when you started taking superdrol your prolly just not taking enough and need to triple the dose at least. Seriously though this could be a lot of things. If it started when you started superdrol, try something else or maybe come off orals for awhile and see what happens. Id give this about another 1-2 weeks and if it was still there I'd go talk to a doc.

Lol I wish the solution was more sdrol. I did drop it shortly after this started and haven't resumed.

Probably one of those things that just goes away. Id try a month of carnivore if it were me. Horrible diet long term but its an elimination diet too could give you a nice reset reduce inflammation without needing deugs

After my vacation "rebound" I think an elimination diet would solve a number of my problems. I'm just kinda enjoying the holidays now and will try for a proper reset in January. I agree, it might sort itself out in time.

But really, right now, I'm thinking GPT might know what it's talking about. I've been supplementing iron for six weeks, I think, and my iron panel is much improved, t3 is just barely in range, and I do think this issue is improving.

So I guess I'll just stay the course and update here if there's any notable changes. I think it's interesting and if there's resolution maybe this will help someone in the future.

 

[derzwerg]

Taurine may help. Also is your blood calcium elevated? Hypercalcemia has some of these symptoms. You can get it if you drive down estro too low.

I do take taurine daily. 5g on rest days and 10g split on training. Estrogen was at 33 right around when this started. Calcium was right middle of the range a couple weeks before that, 9.3mg/dl.

I hate to keep referencing ChatGPT lol but this is above my pay grade. So, forgive me for throwing it in but, GPT does state that calcium is central to what's going on.

Rather than trying to paraphrase and butchering it it I'll just paste what it has said.

Every muscle contraction–relaxation cycle depends on calcium cycling inside the muscle fiber:
Contraction
Nerve signal → calcium released from the sarcoplasmic reticulum (SR)
Calcium binds troponin → actin–myosin cross-bridges form → muscle shortens
Relaxation
Calcium must be actively pumped back into the SR

This is done by SERCA pumps (ATP-dependent)
No calcium reuptake = no true relaxation

Where T3 comes in (this is the key)
Thyroid hormone upregulates:
SERCA pump expression
SERCA pump activity
Mitochondrial ATP production to power those pumps

When T3 is low:
SERCA pumps are fewer and slower
Calcium lingers in the cytosol
Muscle fibers remain partially activated at rest

This creates:
Incomplete relaxation + elevated baseline tone
Not a full cramp — a primed muscle.

Why the pain happens during lengthening
When a muscle that hasn’t fully cleared calcium is suddenly stretched:
Residual cross-bridges are still attached
Stretch pulls on active sarcomeres
Muscle spindle fires aggressively
CNS interprets this as a threat → pain

That’s why:
Pain is sharp
Pain occurs right as lengthening begins
Pain eases if you hold the position
Pain is avoidable if movement is slow
You’re essentially stretching a muscle that is biochemically “on” when it should be off.
Why strength is preserved

You asked a great question earlier:
“If the muscle is contracting, why isn’t it harder to move?”
Because:
This isn’t a full tetanic contraction
Only a fraction of fibers are tonically active
Force production is low
Pain is neural, not mechanical
So:
It hurts
But you can still move easily