Overtraining is a little different than general muscles soreness. When you work out and you feel it the next day, that's normal--and it's good. In order to build muscle, your body actually tears the muscles you have, sends lactic acid and other scientific inner body stuff (remember, I'm an editor/grammar nerd, not a physical trainer) to repair and rebuild the muscles. When you overtrain, you don't leave sufficient time for your muscles to breakdown, rebuild, and recover. When you're high on the endorphins of a good workout, you may not even realize you're overtraining... I'm speaking from experience.
APPARENTLY, it isn't a good idea to do Slim in 6, P90X, then Slim Series back to back. The one week "recovery" in between each workout doesn't really cut the mustard. During my first two weeks of Slim Series, I was doing great. The scale was moving downward, I had great energy, and my legs and arms were getting serious definition. My waist was slimming down even more (which I'll be honest makes me want to do the Snoopy dance). Then I developed a twinge in my lower back. I included more stretches, made sure my muscles were sufficiently warm before starting a workout, but I didn't want to take a day off. I was getting good results! Ever since Gideon was born, I've needes to keep up with exercise (even if it's cardio for 30 minutes) to keep the scale from jumping up a pound or two. (Sadly, I'm not joking.)
Well, the "twinge" turned into severe lower back pain. I was also experiencing the other signs of overtraining: moodiness (I think Shaun's comment was that it seemed like my hormonal flux of my lady time carried over for the entire month--thanks, babe), lack of energy, and decreased results. So I had to put on the breaks. A friend of mine (who is not a doc) suggested I take a month off. I took 2 weeks off (I know I shouldn't put too much emphasis on the scale, but the weight was slowly creeping up with each day of non-activity other than walking or chasing Gideon).
THIS time, instead of doing the Slim Training system 6 days straight, I'm inserting cardio every other day to allow my muscles time to recuperate before tackling the next workout. P90X is designed to alternate strength training and cardio days with yoga and stretching to prevent overtraining, and you get a week of recovery after every 4 weeks. That's why you can go for 90 days and generally not experience overtraining or injury. I was able to go 2 weeks before hitting my wall, and I was stupid to keep pushing through the pain to complete a workout. (It's good to keep pushing if you're in the middle of a set of squats and your glutes and quads are burning; it's not good if you can't lie on your back without lower back pain.)
So there's the skinny on overtraining. Avoid it at all costs! I'll let you know at the end of the week how my updated schedule works. I do feel slight lower back pain (I'm on day 3 of the new schedule) but tomorrow is a less intense cardio day (I'm doing Kenpo X). I'm hoping I can keep working with these DVDs because I love them (aside from the back pain).
I won't lose heart, though. If Slim Series can't be my workout of choice, I've got more options down the pike. (Oh, did I mention I just ordered Insanity? I'm not going to attempt it until June, just in case I have another problem with my back. I must be crazy!)
:c) Keep pushing play.