Are there any positive effects of caffeine?

Effects on the Body:

* Hormones- You can feel the effects of caffeine in your system within a few minutes of ingesting it, and it stays on your system for many hours-it has a half-life of four to six hours in your body. While in your body, caffeine affects the following hormones: * Adenosine- Can inhibit absorption of adenosine, which calms the body, which can make you feel alert in the short run, but can cause sleep problems later. (More on this below.) * Adrenaline- Caffeine injects adrenaline into your system, giving you a temporary boost, but possibly making you fatigued and depressed later. If you take more caffeine to counteract these effects, you end up spending the day in an agitated state, and might find yourself jumpy and edgy by night. * Cortisol- Can increase the body's levels of cortisol, the "stress hormone", which can lead to other health consequences ranging from weight gain and moodiness to Heart disease and Diabetes. * Dopamine-Caffeine increases dopamine levels in your system, acting in a way similar to amphetamines, which can make you feel good after taking it, but after it wears off you can feel 'low'. It can also lead to a physical dependence because of dopamine manipulation. These changes caffeine makes in your physiology can have both positive and negative consequences: * Sleep Caffeine can affect your sleep by keeping you awake longer, thereby shortening the amount of sleep you get, and giving you less time in the restorative stages of sleep, which takes a toll on your level of alertness the next day and overall health. Interestingly, though, caffeine doesn't affect the stages of sleep the way other stimulants do, so it's a better choice than speed or other 'uppers' to use if you need to stay awake. * Weight Many experts believe that increased levels of cortisol lead to stronger cravings for fat and carbohydrates, and cause the body to store fat in the abdomen. (Abdominal fat carries with it greater health risks than other types of fat.) Also, if increased cortisol levels lead to stronger cravings for caffeine-laden foods, the body goes into a cycle that leads only to worse health. The good news, though, is that caffeine can speed up metabolism. Also, it can help the body break down fat about 30% more efficiently if consumed prior to exercise. (You must be exercising to get this benefit, though.) Additionally, caffeine can keep blood sugar levels elevated, leaving you feeling less hungry. * Exercise If caffeine elevates levels of cortisol and other hormones for a temporary boost, after caffeine wears off, the body can feel fatigued and feelings of mild to moderate depression can set in. This can make physical activity more difficult. On the positive side, caffeine has been found to enhance physical performance and endurance if it isn't overused. This, combined with its effect of fat burning during exercise, can actually enhance workouts and enable you to get in better shape if you take it at the right time.