What Happens in the Muscle
Muscles are built from protein fibers; fibers of finite chains as a muscle strive normal wounded in tiny fibrils that gives us the pain of needles. This is nothing dangerous or bad, is simply that the muscle is then repaired and reinforced to withstand the weight next time. So I do not usually because soreness exercise frequently or if you do go to the gym and always lift the same weight.
My first recommendation is to exercise and SI SI try to raise the weight and effort to get results, but do so calmly to strengthen muscles gradually. And while stretching do not remove the laces are very important to keep the body flexible and prevent injuries.
My second recommendation is to eat well to give the necessary nutrition your body to endure not just physical exercise but also life in general. And just as important as diet and physical activity is rest to regain strength.