I'm just starting insanity after two rounds of P90X. I'm only a few days into insanity, but am a lot less sore than I expected to be. I do have some thoughts/concerns with insanity though, namely:

-The workouts are so much shorter than the X workouts, I sometimes feel like they're over before I really get into it. I do obviously sweat a ton and am breathing rapidly most of the time, but I fear I'm so concentrated on just learning the moves and trying to keep my form that I don't constantly contract my core like he's always saying to. Sometimes I'm just breathing too hard to tighten my abs. Maybe I just need to give it time, get to know the moves better, and once I have some strength and endurance built up I can focus more on that ab constricting?

I was getting really great at the X plyo workout and love that I just had to add a few more reps, etc., to keep it a high intensity workout. I also liked that the actual workout out was a considerable amount of time. The insanity warm ups are intense, but manageable. But once the stretching is done, there's barely 20 minutes of actual workout time. Is that really enough?

I was doing the X doubles before, and I'm still supplementing some kickboxing in the AM, then insanity at night. I just feel like this round of insanity is about getting the hang of the program, and I might need to do a second round to really see any benefit. Or maybe a p90X-insanity hybrid would be great since I miss the weightlifting from the X.

Ok maybe I'm just rambling on...but those are my thoughts at the moment. I know, i know, dig deeper...bring it...so long as I keep my butt moving I can't really go wrong!

insanity
 

I just started insanity today so I dont know how well its going to work for me, my biggest issue is I cant find anyone in my situation. Im 5'10 120lbs so losing weight or inches off my waist would be pretty much deadly for me!! im already underweight and eat a ton. Im confused with how I should diet with this program and how to input it on this site correctly!! Im guessing I need to increase my protein and carbs with shakes etc?

If you're underweight you should talk to a nutritionist on how to gain weight safely.

I would suggest weight training with limited cardio exercises. I am assuming you would like to be more fit and defined. Cardio won't do it for you. Lift heavy (use enough weight to perform only 4-6 repetitions before you cannot perform the lift with good form). If you're not an experienced lifter get instruction. Increase your protein intake to the .5 to 1.0 grams per pound of lean body weight range. An increase in your total calories so you are in a calorie surplus is neccesary for weight gain but try to maintain your protein around 30% of your calories. Body builders call this bulking. Some increase in body fat is expected but if your metabolism is as you stated this should be easy for you to shed once you build some muscle.

I did the Insanity program. I really noticed the results in the second month and closer to the end of the program. It is hard but worth it. I did adjust my diet and started to mostly eat smaller more frequent meals that were more nutritious with some "bad" meals to remind myself I was still alive. I did not follow the program's diet though. I lost 4% body fat and went from 222 lbs to 204. I had lifted weights and mixed cardio in for several years. I am back to lifting again but with more of the HIIT mentality after I saw how it worked in Insanity. The hardest part of the program is the burnout near the end.