1) When I do a 3-mile or 5-mile run, I run for time and try to finish with nothing in the tank. The closer I get to the end, the more I push myself, because I know I don't need to sustain the effort much longer. When I stop running, I suddenly get very light-headed and dizzy. It never happens while I'm running. I walk briskly while I'm warming down, but that doesn't prevent it. Why does this happen? Is it dangerous?

2)  Sometimes after jogging a while, or cycling a great distance, my head begins to spin and I feel as if I'm going to pass out. Is it normal to have feelings like these, and if so, how intense should these feelings be?

I am currently trying to revise my eating habits to eat less often (I'm a throughout the day snacker, and normally don't eat meals). Is it okay to replace cravings or "boredom eating" with herbal teas? I was told that tea is a no calorie drink, and yet it fills me up when I'm hungry. I have started to replace most of my cravings with tea now, so that I actually eat a lot less than before. Is tea healthy for you if it is no caffeine, herbal, and I use honey to sweeten it? I am not used to drinking much of anything in the day and am fairly slim, so could the extra water intake have any weight gaining effects on me? Could this be a healthy diet?

I have been chewing and spitting large amounts of food (pretty much always sweet stuff — pastries, chocolate, etc.) almost every night for eight or nine months. I am eating a healthy, balanced diet otherwise, maybe a little on the lower caloric side (1300 to 1500 calories per day). My chewing and spitting sessions usually follow a balanced meal. I know this is a type of eating disorder. I have done a lot of research online and I know that there are side effects, although they vary depending on who you ask. Some sites mention that chewing and spitting activates the release of insulin and results in hyperinsulinemia, insulin resistance and weight gain. Is this true? How long would it take to develop these problems? Are these reversible if I were to stop this behavior?

I've heard of body suits that increase sweating during exercise. Then I heard that Saran wrap had the same effect. I want to shed pounds but first I wanted to know if wrapping plastic wrap around the stomach helps burn fat during exercise.

Does altitude affect calorie-burning? That is, if I do the exact same workout twice — once in New York City and once in Colorado — will I burn more calories at the high altitude? What things DO affect how many calories you burn in a workout?

I have heard that if you exercise/work out in the morning before you eat breakfast that it will cause your metabolism to increase throughout the day, helping you to burn calories. Is this true?