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 start practicing meditation, yoga, or tai-chi?

Recently I've been thinking a lot about ways to relieve my stress and other mental problems such as OCD and ADD and I have been hearing that meditation, yoga, tai-chi, etc. can possilby help with these problems that I have been suffering with all my life, but I am very confused as to which one would be the best for me.

Also, if I find out which one would work the best for me, how would I go about finding someone that could teach me these things? Or is a book a good way to go? If a book is a good way to go would you suggest one of those "The Complete Idiot's Guide to..." books?


Is my hair addicted to dandruff shampoos?

I have dandruff that responds well to over-the-counter shampoo. Ergo, I have been using the stuff almost exclusively for ten years. No brand in particular, sometimes zinc pyrithione (the blue stuff!), sometimes coal tar (the smelly brown stuff!). Anytime I switch to non-dandruff shampoo for like three to four days straight, I get my dandruff back. I worry that I might be addicted to dandruff shampoo. Should I worry?


Are there risks involved in hot yoga?

Hot yoga is becoming more popular every day but there is a lot of conflicting information regarding benefits versus injuries. Most of the information does not quote sources and is therefore is difficult to follow up on. It has unquestionably helped me become a more flexible person but there is a lot of information on the net regarding horrific injuries including slipped discs, muscle tears, neck injuries, emotional problems, and even strokes. Is there a research-based, or at least a factual breakdown on the health benefits of stretching at temperatures above body temperature versus the injury risk of exercising at temperatures above body temperature?


How many rest days should I take between runs?

I wanted to know how many days of rest is recommended between workouts. I heard it was three days on to one day off...is this enough? I workout on a treadmill for 50 minutes every day and have for the last 14 months. I was not aware of how rest played a very important role until I recently read a brief article on it. I guess my question is, do I need to take that day of rest and how important is it?