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

I am a second year Nutrition student and have a question about protein and endurance athletes. Why are their protein requirements greater than they are for resistance athletes? Is it because the muscle glycogen stores get depleted over a long period of time with intense exercise? If so, should they consume more carbohydrates than resistance athletes, with a low glycemic index prior to their workout?

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 researched health and nutrition online for a while now, and I work out not only with weights and yoga, but martial arts and mountain biking, as well.

Lately while researching online, I've found that a lot of nutritional value charts conflict in numbers. Some charts say that skim milk contains eight grams of protein, some charts say skim milk contains 13 grams of protein. Which charts are right?? This is incredibly frustrating and confusing. I did find out that there is nutrition software available, but it's so expensive and it comes with lots of extra things that only doctors need really, like making charts for patients and what not.

Also, I found information on one site saying that adults should consume 0.8 grams of protein per however many kilos you weigh (I weigh 82 kilos, so that means 66 grams of proteins per day). Another site said that adult females between 25 to 50 kilos just need 55 grams of proteins per day. Also, it's not just protein intake that conflicts with all of these charts online.

If you can help out at all, it would be greatly appreciated. Thank you in advance.

I'm on my school's track team and I don't know if I'm doing something wrong. When I run, my testicles seem to get in the way and are sore afterward. They seem too big. Is that possible? The jocks I've tried don't help much and we are issued stretch shorts that don't hide them well at all! It's embarrassing and sometimes it hurts to ride my bike, too. They have always been that size but is there something else I can do?

I just got a diet tea that contains senna. How is this herb bad for your health? Is it unsafe to drink it everyday to lose weight?

Thank you very much.