 [ Symptoms ] if 6 year old child has fever over 100 f and tachypnea and tachycardia should he go to er [ Disease ] if you have fibromyalgia and want to start exercising it is important to start slowly begin with stretching exercises and gentle low impact activity such as walking swimming or bicycling muscle soreness is normal when you are just starting an exercise regimen but if you have sharp pain stop and call your doctor you may have overworked or injured your muscles