I have been training for a half marathon since June. One thing I have learned is you can NEVER drink enough water!
Another thing I have learned: WEIGHT DOES NOT DICTATE HEALTH According to BMI charts I am still "overweight". I can run over 100 miles in a month so if you ask me, I am healthy. However there are plenty who are in a "normal" weight category who do not have the endurance to exercise like I do. I feel really good all the time. I am trying to convince myself that HEALTH is more important than WEIGHT.