400
Not necessarily, no.
You can burn 150 cal during 30 min of sex, so I'm guessing around 300 for an hour..
Lift weights, ride your bike hardcore, and sweat blood.
a lot because it's sweat
I would say the eyebrow
headbands are bands that go around your head to prevent sweat dripping onto your face :)
Sweat is primarily prevented from dripping into your eyes by the brow ridge and the natural contour of your forehead, which help direct sweat away from your eyes. Additionally, many people employ techniques like wiping their forehead with a towel or using sweatbands. The body also produces less sweat in cooler conditions, further reducing the likelihood of it running into the eyes.
When you sweat it burns fat. If you exercise hard enough you sweat.... burning calories.
so that sweat dripping down hour back is obsorbed by the hairs
There is absolutely no way to measure that because they are not at all related. You can sweat by sitting in a hot room and not moving (hardly any calories burned), and you can burn tons of calories by shivering or swimming in a cold lake (hardly any sweat).
Eyebrows protect the eyes from dust, sweat, and other foreign particles. The hair on your brow blocks sweat, water and dirt from dripping down from the forehead and irritating the eye.
Keeping you warm is not a function of sweat. Sweat protects a person from becoming overheated on extremely hot days.