I posted this in the success story section but I thought it would be appropriate to add it here also.
The below post was in regard to my first 2 major successes so far on PB, the first being under 250lbs between Christmas and New years.
Preparing for the half marathon on 1/15/12, I went for a run last Wednesday night, 6 miles, and both my hamstring and calf cramped 5.5 miles into the run. This freaked me out and I realized that I was dehydrated, so starting Thursday, I drank a gallon of water a day and increased my carb intake for the additional fuel needed for the race. As of Sunday morning at 4:30am I weighed 257 lbs (+17lbs in 3 days), so obviously I was severly dehydrated. That little cramp session was a great wake up call. I ran the race and did not walk and finished in 2:32.35. I weighed 253 after I got home.
As of this morning I am back on PB 100% and focused on dropping below 200 lbs by June 1st.
I did learn a tremendous amount about my body, capabilities, nutrition and hydration over the past week. Definetly watch out eating very low carb if you are planning exercises that will be for long duration (1+ hours). Your muscles will need enough fuel to keep them going for that extended time. I never had a problem hydration wise, during the 1 hour workouts.
Good luck to everyone, set your goals and get after them!