it is possible that you are experienceing a vitamin or nutrient deficiency.
Magnesium is what came to my mind.Magneisum and calcium work together to regulate muscle and nerve tone. In Nerve cells it acts like a chemical gate blocker. As long as there is enough magnesium, cacium can't rush into the nerve cell and activate the nerve. So magneisum keeps the nerve relaxed, and that keeps muscles from over contracting.
Deficiency symptoms can include changes in muscle function, muscle weakness, tremor, spasm, right side leg cramps,(left side leg cramp is calcium def) and other symptoms may include some or any of the following: frequent sighing, lack of appetite,elevated blood pressure, irregular heart rate, difficulty swallowing,insomnia, TMJ, Neck pain, twitches tingles and zaps, headaches,grouchyness, depression, nausea, IBS,Chronic fatigue,Anxiety,memory loss, Chronic pain, fibromyalgia, inattention, confusion, or changes in nerve function. Dimagnesium Malate ###-###-#### is a form that the body can use because it recognizes it as food. Bathing in Epsom salts , 2c to a bath, can give magnesium through the skin, is calming before bed and help you sleep longer.Some people put epsom salt in coconut oil and rub it on the skin. it is very softening and can give you magnesium that way. Increasing protien can help to improve magnesium uptake. We must have plenty of magnesium everyday. Foods high in it are pumpkin seeds, boiled spinach, Swiss chard, Chinook salmon, sesame seeds, Baked halibut and brocoli.
Vit b4 and b12 affect nerves. Take a b complex vitamin if you supplement because many of the b vits rely on eachother for uptake. Some b vitamin deficiency symptoms include calf muscle tenderness, indigestion,oversensitive to noise or light, fatigue,anorexia,vauge pain (all b1), and other b deficienceis include irritable, tiredness, weakness or loss of muscle control, chapped and cracked skin, Mouth or tounge sores, low blood pressure, heart skipping, memory loss, numb or burning hands or feet, carpal tunnel, rosacea, tearing- burning and itching of eye, and more.
If you excercise you are putting more demand on your body for nutrients. You should be supplementing.
I would also suplement with FULVIC ACID (found online). It has 60 trace minerals that are otherwise hard to get in an ionic form. Farmers use fulvics to help their crops grow!