While I agree, totally, that diet is key...I do have an example of my own to share, about the exercise side of things.
Back in 2007, when I came to Spark to lose weight, I had already dropped about 10 pounds. About a month in I decided to begin to strength train. I went at it, full body, and was feeling great. That is, until I stepped onto the scale and it showed I had GAINED 8 pounds! What??
My diet was tight, my calories were spot on, my sodium count was bare minimum...This can't be right!
But, instead of "quitting", I kept plugging away..kicked the scale to the curb..and began to gauge my progress on how I was feeling, how I was looking, and by taking body measurements.
After about 6 weeks, not only had I lost a TON of inches, but when I pulled the scale back out, the re-gained (mystery) pounds had disappeared and it was from this point on (thanks to all the new muscle), that the scale never stopped dropping (2lbs a week became the norm) until I was about 50 pounds smaller.
So, don't give up! What will that do for ya?? Sometimes the new muscles retain fluid, as a protective measure, to ensure their repair and growth. After about 4 - 6 weeks the fun begins!!