You may feel muscle soreness for a few days after trying something new. This may mean the activity you did was too strenuous or involved muscles you do not use often. Muscle soreness is normal and will usually go away in a few days. Soreness is different from pain . If you ever feel pain in a muscle or joint , you should tell an adult or go to the doctor.

Sometimes you may develop an ache on the side of your upper stomach during activity. Nobody knows exactly what causes a sideache . Stretching the side that is hurting, taking deep breaths , or putting pressure on the ache with your hand may help. At other times, you might have to rest for a few minutes until the ache goes away.