I was an athlete and exercised intensely 5-6 days a week for 20 years before getting Hashimoto's 7 years ago. So I know well what is normal soreness and duration after a hard workout. The first "muscle symptoms" I noticed came a couple of years after my diagnosis. It came in the form of hip/knee stiffness. At first I thought I wasn't warming up enough, or that it was my new sedentary career (which I'm sure didn't help). I know now that "stiffness" was residual soreness from previous activity. I added an long warm-up before every workout only to be stiff again the next day. Normally, 3 days after I did squats my leg soreness would be gone. Little by little over the last 3-4 years this soreness has gotten worse. This happens to other muscles too, i'm just using squats here as this one affects me the most. Any muscle I work has this issue, but the hamstrings, deep calf muscle soleus, and my lat muscles cause me the most discomfort. I get EXTREME MUSCLE SORENESS for 6-9 days now......i forgot to mention I would get sever muscle spasms/cramps just by flexing a muscle.
I've tried massage and I've done the TENS unit electric stimulation. They only help cover the pain for an hour or 2. And deep tissue massage in those areas of your soreness will cause you to scream/cry. I even took 6-months off and only did swimming.....but the moment I lifted weights or tried to do hill sprints again it came back. I've read that Hashimoto sufferers muscles change from Type II (fast twitch) to Type I (slow twitch), I think that that is the result of us not being able to do intense exercise without encountering either an injury or the extreme soreness which trains us with pain to back off. Others claim it is a cellular issue. Probably it's both. I'm still fighting it. But muscle strains are also very easy to get with this problem in addition to constantly being extremely sore.
I now get extreme soreness after doing a few sets of squats that lasts anywhere from 6-9 days. My muscle fibers get torn worse than a healthy persons and they recover much slower. For someone who can't relate, think back to a time when you took 6-months off from the gym and then one day hit the weights hard. It is like the worst soreness you've ever felt that hits you 2 days after the exercise (DOMS), except this lasts at least a week or more and can hit me by that same evening. I believe the autoimmune Hashimoto's is acting on my muscles as well, somehow my cells are not getting what they need, there must be inflammation. I once saw after sitting in a hard chair a line of bruising where the chair had pressed on the back of my legs during that soreness period which shows me that I have internal bleeding inflammation that is going on after exercise (much more than normal). ****The muscle fibers are being torn down worse then normal and they are recovering slower than normal****
I take 5g of creatine monohydrate powder daily, which seems to help a tiny bit (might just be my imagination), at least with the joint stiffness. I listen to my body and if an area is still sore/stiff I wait until it's not before doing that exercise again. I swim 3 days a week to fill in the cracks. I'm still looking for a solution, I don't have med insurance at the moment so I'm limited as to what I can experiment with. I walk as well, but even walking leaves me with sore achilles tendons. I've taken L-cartinine (both types), selenium, vit-D, magnesium, etc.....nothing helps with the muscle soreness/stiffness.
I take 75 mcg of Liothyronine (T3) daily. I don't take any T4 since 7 months ago. I'm thinking about trying the AIP diet to see if that helps with inflammation, also thinking about taking a little T3 right before I go to the gym to see if it helps.