I just started p90x and I am wondering if I should do the lean version? I am 24yrs female 5 foor 4.5 and 138 pounds and am hoping to get lean muscle definition while not putting on any more weight. also is there a specific diet plan for the lean program that is different? you advice would be appreciated! thanks =)

If you're not aiming to get bulging muscles then lean is for you. I'm not sure if there's a specific plan for the lean program though.

I totally disagree, you will not get "bulging muscles". I am doing Classic, and am continuing to get smaller. HOWEVER, when you say you don't want to gain weight, do you have any weight to lose? I gained 5lb, but I lost 4% bodyfat and that 5lb was all muscle. I went down 1 size, and am close to being down 2 sizes. I started at 140lb, 5'7", and am now 145lb. I was close to my goal weight-wise, and so the muscle I gained cancelled out the fat that I lost. I had to let go of the number on the scale. I am in Round 2 day 160.

There is no specific diet plan for lean, just follow the regular plan

Agreed. P90X is not exactly synonymous with "bulging muscles". It's more for that ripped look IMO. I don't think you have anything to fear in that regard by going "Classic". Look at the women in the resistance videos. They're all grads and not one is even close to bulky if you ask me.
My wife has this fear of resistance training. She thinks she's going to turn into a Ms. Olympia contestant overnight so she just doesn't do weights. It drives me nuts. It doesn't help that she goes to a women-only gym where many of her peers have this same mis-guided notion. Heck, even the so-called trainer there suggested she only do cardio. Argh!! Sorry for going off on a tangent.

Do the classic. Listen to Tony, he says, for size do more weight, less reps. For lean, do smaller weight, more reps. Why is this so hard for people to understand? It takes muscle to burn fat.

I think it may be confusing to newbies because Tony himself said that many women like the Lean version which basically has a little more cardio, and substitutes Core Synergistics for one of the resistance/ab ripper X days. I started doing Lean for Phase 1, tried a week of Classic for Phase 2, then returned back to Lean for the rest of my first round. I thought I'd prefer the extra resistance over Core Synergistics... but found I kinda missed Core Syn (go figure). Maybe I'll do Classic for Round 2. But really, it all depends on what you want to do.

It is a matter of preference. Many women like cardio so the lean version is for them. Me? I love lifting so I am doing classic and going for more weight / less reps. I want those muscles.

I'm a 5'5" female and I'm doing the classic version. I've actually lost 6lbs. Honestly, as recently as June I weighed about as much as you. I was 135lbs. If you stick to the 1800 calories a day, it is likely you may lose some weight all while building muscle and getting toned. I haven't seen female that turned into a body builder just by doing p90x.

Classic is what most people choose to do. Think of it more as strength training and fat burning. It actually seems to take longer to build mass than what you would think. Cardio focuses on your heart. Yes you may sweat alot but resistance training will continue to burn fat long after your heart rate comes down.

I enjoy both cardio and reststance training. Together they can produce amazing results.

What ever you choose stick with it.

Rip

thanks for your repilies they were very helpful! i have decided to stick with p90x classic. this is my first week and I am on day 4 and i love it! its such a challenge and i look forward to seeing the results and getting shredded! I have been using low weights/higher reps so i dont think I have to worry about gaining! thanks again!

How low are your weights? If you are lifting too lightly, you will not be building enough muscle to burn the fat. Don't lift "barbie" weights if you can lift more.

During Round 1, I got up to 10-13lb for biceps, 5-10lb for triceps, 8-10 for shoulders, and 25 for lawnmower/heavy pants. I am now able to do curls with 20lb, and my arms are NOT bulging muscle. Do not be afraid to lift real weights.

Yes, no matter what rep range you're lifting in the last 1-2 reps should be very hard for you to complete - whilst maintaining proper form. In fact, I try to go to failure but that gets very tiring when you're doing so many different excercises in one workout.