Last night, I went to the gym for the first time in years. I weigh myself everyday just to keep track of how I do after each day. I worked out for about 33 minutes yesterday on the elliptical. I ate decent and stayed within 1800 calories. I did eat a late dinner though. I weighed myself today and I gained 4 pounds! Is it water weight? This is a bit concerning for me. Help!

Yes, it's water... Unless you ate 14000 calories in your sleep!! Be sure to drink plenty of water over the next few days and it will equalize in a few days. Eating foods with high sodium content, more carbs than usual, exercise (esp if you have sore muscles) and hormones can all be causes of retained water.

Thanks! I just need to power through these next few days.

Definitely water weight...your muscles retain water to repair themselves after working out. Your just starting at the gym so the scale is going to be showing some funky numbers the next few weeks or so...Don't worry. I'm looking at my week weighins right now, and the first week I hit the gym I had a 5 pound gain, followed by a loss of those same 5 punds, followed by regaining those 5 pounds and holding onto them for two weeks...then I started seeing a steady loss...

Be pacient...and a big congrats on starting up at the gym...