Ignoring your body clock and changing your body's natural rhythms can not only make you deperssed, anxious and accident prone, it can lead to much more serious health problems. For example, heart disease, fatigue, our ulcers,muscular pain, and frequenent viral infections can all result from trying to outsmart our body clocks. Altering our pstterns of sleeping and waking dramatically affects our immune system. While we sleep the body's repair mechanisms are at work; when we are awake natural killer cells circulate around our bodies and cause more damage. Our digestive system is affected, too-high levels of glucose and fat remain in our bloodstream for longer periods of time and this can lead to heart disease.