I am not a doctor, but this is how I rationalize it as a person who makes lifestyle choices every day.
Intense exercise, stress, exposure to toxins (which I personally believe non-placebo mRNA vaccines can cause this), smoking, excessive alcohol, processed foods, hydrogenated oils, diet low in antioxidants, aging, and combination thereof can cause free radicals and oxidative stress which in turn can cause inflammation and pain, particularly where there has already been cell damage.
Whether cell damage has been caused by covid, vaccine, gene therapy, toxins, hyperimmune/autoimmune disease or other pre-existing condition, or combination in a particular individual, I don't know.
However, my understanding is a diet high in antioxidants, and the long list of other vitamins and minerals which help detox toxins and repair cells (i.e., varied diet consisting of lean meats, red meat every four days or so, seafood, spices, greens, onions, garlic, dark chocolate, nuts, seeds, and bright, colorful fruits and vegetables, and healthy dose of sunshine) while still maintaining good pH levels is best defense.
It is also my understanding that hyperbaric oxygen therapy may help cell damage, but I find box breathing and stimulating the lymphatic system through massage, light to moderate exercise, and exposure to hot/warm/cold as more affordable option requiring no equipment.
Feel free to correct me if I am wrong. I'm just an average person and this is my basic understanding.
More detail on specific vitamins, minerals, and supplements can be heard here from Dr. Judy Mikovits: