So, I made a change in my routine...like I usually do every two weeks....

On Monday, I had a super great workout, highly intense and probably a few minutes too long (60). The next day, I am really sore, especially in the chest and arms. No problem, I like feeling sore.

Then, Wednesday comes and I am still very sore. Now, I am not sure what to do. I go online, a little research later, I have no definitive answer as to whether I should train again. I decide that I am anal and if I skip it, I'll feel like crap. So, off I go and do the same exact workout with the same weight, and even increase reps on some of the exercises.

I worry that I may have pushed too hard. Thursday comes, NO soreness at all. Today is Friday and no soreness again! Does anyone have any clue why working through the soreness made it disappear??? Did I do a bad thing or a good thing? lol I am just really curious now!

By the way, I am not new to weight training...I've been at it for a year now. If that helps at all.

I'm sure the fitness EGGzperts will be here soon to give you a really good well thought out explanation (I can't wait to read it either) but I do know that when I am sore, one of the best ways to get through it it to exercise that muscle group again to increase the blood circulation. Then I feel much better.

yoo-hoo, Meg-Mel, where are you?????

I have read that when you work a muscle group very hard, you get sore due to lactic acid build up. When you re-work that muscle group, you release the lactic acid and you feel better.
I have no answer as to why it made you sore the first time and the 2nd time, you felt better. It would seem that it might make you feel better at first but then the work out would cause another lactic acid build up, causing more sore muscles.

I think you worked thru the swelling, stiffness and any l/a and you just didn't build up as much this time to cause pain. Also, drink lots of water to keep your muscles hydrated and flushed.

A similar but different story...used to be if I had a headache, I should just forget cardio. Lately, doing the treadmill/exercising actually makes my headaches go away! Amazing, before if I had tried that, I'd have to stop midstream but not anymore. I guess I have lactic acid in my brain now. :0

If I am still sore, when it comes to the next workout, I still do it. I alternate cardio and lifting, so after a heavy lifting day, the cardio loosens my muscles up, and the stiffness goes away. It has to do with keeping the blood circulating throughout your body. I know that if I take time off, I feel more soreness. This is apart from any injury or arthritic soreness that might occur. That's a different story.

Lactic acid, if not used as fuel right then and there, gets stored through the metabolic system. It does not build up for the next workout.

Thanks for all the ideas. At least I know what to do next time.