I know lots of people who have used the program, and there's one guy in Champaign who is a Beach Body veteran. He lost a ton of weight doing P90X and now works for the Beach Body company. Like Bobbi said, it's a huge fad right now. But what lots of people don't know is that P90X is actually part of a 4-part series, and it's the 3rd component. The series starts with Power 90, then progresses to Power 90 Masters, followed by P90X, and finally P90X Plus. Since many people are only familiar with P90X, they'll jump right into P90X without working their way up the ladder first, which I think could be potentially dangerous for novices or people with health conditions. I have tried the P90X workouts myself, and, personally, I don't like them. Everything is high-intensity training. There are no intervals involved, so you're only working one part of the spectrum the entire time. Will you torch lots of calories like they promise? Yes. But those calories are primarily coming from your carbohydrate storage, or potentially even tapping into your protein storage, depending on how high your heart rate gets. This is probably why Cari's brother gained so much of the weight back, because he was most likely burning the wrong types of calories, and because high-intensity-only workouts train your metabolism to function at that high end of the spectrum, so if you stop reaching that intensity, you stop yielding results.

I have also tried the Slim in 6 program, which says that you will get ripped in just 6 weeks. Sounds appealing, doesn't it? But what they don't tell you before you buy the program is that the plan consists of 6 days of exercise per week twice a day. You're instructed to do cardio for at least 20 minutes in the morning, then do the 60-minute Slim in 6 workout in the afternoon. Twice a day, 6 days a week for 6 weeks??? Who has the time and energy for all of that?! In addition, they provide you with a generalized eating guide which boils down to about 1200 calories a day. Talk about extreme diet and exercise, and it's not even personalized. Like Bobbi said, people vary. For some women, 1200 calories is appropriate when dieting, but for most women 1500 calories is more accurate if you have to generalize, because it allows them to create a calorie deficit resulting in weight loss without messing up their metabolism by putting their body into starvation mode.

Of course everyone is different, but I personally enjoy engaging in a variety of activities (high intensity, low intensity, and intervals) so that my body can be efficient at burning calories in multiple heart rate zones, instead of just one. If you really want to be accurate about losing weight, I would recommend getting a metabolic assessment. There's a fairly new system out called New Leaf. It assesses your resting metabolic rate (so you know the bare minimum of calories your body needs in order to function on a daily basis and not go into starvation mode), and then you participate in a submaximal exercise test for about 15 minutes so that it can assess your active metabolic rate (i.e. in which heart rate zones your body is most effective in burning calories, how many calories you burn per minute in each zone, what percentage of those calories are coming from fat or carbs, and at what point do you reach your threshold and begin to burn protein). Then you get a 12-week personalized cardio regimen, so there's no guesswork involved. Ideally, at the end of the 12 weeks you go back to get re-tested, and if you followed the plan your calorie burning efficiency and range of heart rate zones will have expanded. I got mine done, and it's a great tool. If I opt to do something different like pop in a workout DVD or hit up a spinning class I can strap on my heart rate monitor and manage my own intensity. For example, I can pause the DVD and let my heart rate come down if I start exceeding my threshold, or I can increase the resistance on my bike to take me into a higher calorie-burning zone. If you're in Champaign you can get tested at Nutrition@Work on Neil street or at the ARC on campus. Otherwise, there are gyms and facilities nationwide that offer New Leaf testing, so just ask around or google it. Cool stuff!