its may be a temporary one. but keep in mind, before beginning any exercise session, warm up with a few minutes of aerobics to warm the muscles and end your workout with some light stretching to cool down. Never chew gum or suck on candy while exercising. If your mouth tends towards dryness, stop your workout and have some water. Stop exercising if you feel any sharp pain, especially in your head, neck or lower back as these are particularly vulnerable to injury with abdominal exercises.