I started going to the gym on Monday after several years of sitting and I've done nothing but gain both days! Almost 3 lbs now! Am I missing something? Is this normal?

I think it's normal, at least for me.

Anytime I've started a gym regimen I always gain first. Maybe muscle?

That much gain in such a short time is always water weight. Keep doing what you're doing, other than stay off the scale. If you stress over every little pound, then you would be better off to weigh no more than once/week.

Edited August 20, 201412 yr by Kindle

I wouldn't worry too much. Maybe you're drinking more Water because you're working out. Maybe you need a good poo... or maybe you're body's retaining some water from lactic acid. No way 2-3 workouts built up so much muscle you weight 3 pounds more.

It's ok... keep exercising!

This is a great article explaining why people gain weight when starting a new workout routine:

http://www.sparkpeople.com/blog/blog.asp?post=why_the_scale_goes_up_when_you_start_a_new_workout_plan

Yeah, it's most likely Water and temporary. Your body is all "WTF, yo, why are you doing this to me?:" It's kind of whining. It'll get over it. And once it realizes you are not going to stop working out that water weight will go away. Continue to work out and hydrate.

You will gain muscle (therefore weight) if you do weights. But that's awesome! Muscle burns calories. Work those weights!