In organic chemistry, a hydrate<span> is formed by the addition of hydrogen to another molecule to form a compound. ... By contrast, an anydrate or anhydrous material </span>does <span>not contain any water molecules. The water is usually removed by suction or by heating the substance to a high temperature.</span>
Because some of the weight is in your muscles.
It's caused by a buildup of lactic acid, but is really a signal your muscle is using to let your brain know it's running out of energy. Eventually, you'll build up enough endurance that your muscles won't freak out so soon.
