What are circadian rhythms; how do they normally affect our motivation and alertness; what are the detrimental effects of interrupting these rhythms through travel, shift work changes, or "burning the midnight oil;" and how can these detrimental effects be treated?

What will be an ideal response?

Answer will include that every 24 hours, the body undergoes a cycle of changes called circadian rhythms (circa: about; diem: a day). Throughout the day, activities in the liver, kidneys, and endocrine glands undergo large changes. Body temperature, blood pressure, and amino acid levels also shift from hour to hour. These activities, and many others, peak once a day. People are usually more motivated and alert at the high point of their circadian rhythms. People with early peaks in their circadian rhythms are "day people," who wake up alert, are energetic early in the day, and fall asleep early in the evening. People with later peaks are "night people," who wake up groggy, are lively in the afternoon or early evening, and stay up late. Circadian rhythms are most noticeable after a major change in time schedules. Businesspeople, athletes, and other time zone travelers tend to perform poorly when their body rhythms are disturbed. If you travel great distances east or west, the peaks and valleys of your circadian rhythms will be out of phase with the sun and clocks. For example, you might be wide-awake at midnight and feel like you're sleepwalking during the day. Shift work has the same effect, causing fatigue, irritability, upset stomach, and depression. Adjusting to "jet lag" is slowest when you stay indoors, where you can sleep and eat on "home time.". Getting outdoors speeds adaptation. A few intermittent five-minute periods of exposure to bright light early in the morning are also helpful for resetting your circadian rhythm. Bright light affects the timing of body rhythms by reducing the amount of melatonin produced by the pineal gland. When melatonin levels rise late in the evening, it's bedtime as far as the brain is concerned. There are few college students who have not at one time or another "burned the midnight oil.". At such times, it is wise to remember that departing from your regular schedule usually costs more than it's worth. You may be motivated to do as much during one hour in the morning as you could have done in three hours of work after midnight. You might just as well go to sleep two hours earlier. In general, if you can anticipate an upcoming body rhythm change, it is best to preadapt to your new schedule. Preadaptation refers to gradually matching your sleep–waking cycle to a new time schedule. Before traveling, for instance, you should go to sleep one hour later