Does sweating release toxins?

After practicing yoga in normal temperatures for years, I recently attended a heated yoga class (heated quite hot: 95 to 100 degrees!). The experience left me dizzy, nauseous, and completely enervated. Afterwards, I expressed my concern to the teacher, asking why the studio needed to be so hot. She "explained" that by sweating, supposedly the body releases "toxins" and that my nausea and dizziness must indicate that I need to "detox." Personally, I think I was suffering from heat exhaustion. I've heard this silly explanation more than once, as many people seem to believe toxins are released through sweat. But is that true??? And — next question — doesn't exerting oneself in extremely hot temperatures seem like a recipe for dehydration? Are their any benefits that make it worthwhile, or is all this heated yoga just nonsense?


How can I put on a condom if I can't retract my foreskin when I'm erect?

I believe I have a mild case of phimosis. When my penis is not erect, I can retract my foreskin all the way back to reveal the glans. However, when I have a full erection, it is impossible to retract the foreskin to that extent. I can only retract it to reveal the slit and top part of the penis. Due to this problem, I have a question about condom use. I'm still a virgin, so I have never experienced intercourse using a condom. When I read the instructions on how to use a condom, they almost always instruct you to retract the foreskin completely if you are not circumcised. Since I cannot retract the foreskin while erect, is it still possible to use a condom without retracting the foreskin, and will this complication affect slippage of the condom or sensation problems during intercourse? On a side note, why is it recommended to retract the foreskin fully before putting on the condom? Thank you in advance.


Do I need to use condoms if my boyfriend might have an STI and not know it?

If my partner and I have been monogamous for three years (and I was a virgin before we met) and my partner tested negative for the HIV virus (twice, about two years ago, with a six-month gap between the tests) is it safe for us to use a birth control method other than a condom? That is, are there still any STDs that my partner might have without knowing it, that we should be worried about, even though nothing whatsoever has seemed wrong with either of us for three years and my partner has had several regular annual physicals in that time?


Does exercising on an empty stomach maximize fat burning?

I have recently learned that in order to burn fat as a fuel, your body requires carbohydrate. Up until this point I had been doing cardio training first thing in the morning on an empty stomach, as I had read that this is optimum for fat burning. However, now I have a small carbohydrate snack before I train in order to prevent my body using lean muscle tissue as a fuel. Today I have again read in another book that training on an empty stomach first thing in the morning burns the most fat. I am a little confused over the best thing to do! I train with weights twice a week and do cardio three times per week. I do want to maintain my lean muscle, but am looking to reduce my body fat.