What is the most efficient way to lose weight with working out? I am 5'7" and weigh 155. I want to lose 25lbs, putting me at 130lbs, but more important than losing the weight is keeping it off and maintaining a healthy lifestyle FOREVER.

I am 25 years old and in my past I have been a habitual yo-yo dieter. I'm over that now. I know how bad that is for me and I am ready to commit to a sustainable lifestyle that will eventually get me to (and keep me at) the weight I want to be (which is between 125 and 130lbs).

How often should I be working out? What should my workouts consist of? Please be specific with respect to time, exercises and schedule (days on/off, etc.)

Thanks for your help and insight.

D