Can you tell me a way to figure out my basic metabolism?

Why is it I can always run a greater distance on a track than I can on a treadmill? On a track, I can run five or six miles, but on a treadmill, I can only go a maximum of three or four, then I tucker out. Is it because I get more bored on a treadmill, or is there a more physical explanation?

I have started spinning and I absolutely love it. Currently doing it about 3 times per week. My boyfriend says that spinning will cause permanent damage to my female genitalia, such as damaging the nerves, leading to reduced sensitivity and ultimately impeding my enjoyment of sex. I always wear the appropriate padded shorts. Is this true or not?

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?

I swim three times a week for 40 minutes and sauna for 15. When I come out of the sauna my face is beet red and stays that way for about 1/2 hour — is this a sign of something wrong? Also, is it bad to work-out (sit-ups, push-ups) in the sauna?

I am a 29 year old woman. I am interested in increasing my muscle mass. Could you please tell me what steps to take in weight lifting as well as in changing my eating habits for a healthier diet?

I am a woman who has a family, full-time job, and a very busy life, generally.

Three years ago, I joined a local health club because I was not getting enough exercise. Since then, I have tried to work out three times a week. Every time I exercise on the treadmill, even though I am not running but only walking fast, I experience leg pain in the back of my calves. I have tried stretching to warm up but nothing seems to help. Do you have any suggestions? The pain in my calves is preventing me from increasing my speed and improving my conditioning. I would appreciate any suggestions you might have.