Sore muscles

Hey everyone, I was just wondering what the whole deal with ice baths is...I know some types of athletes--gymnasts for one will sit in bathtubs filled with ice and ice water after a workout, especially when they're getting back in shape--but what is the actual rationale? I'm just curious because while we are building up our yardage and getting back into swimming shape I am feeling the burn because I am also speedskating 1-2 times a week, just started lifting again and I take a spinning class 2 times a week. In other words, at the moment, my body is really holding together pretty well, but I can definitely feel the difference in the water--I've slowed down considerably but I would imagine that is just a temporary set back because my body is busy repairing and re toning and re tuning. Thanks! Oh and completly off the subject of my question but there's a freshman on my team who is a very good swimmer, but she's working so hard and pushing herself to such a point of high stress on her body that I just feel for her, because she has bad shoulders and I completely understand that desire to really go out in practice and impress the new coach and teammates and stuff--I was exactly the same when I came to school or changed teams, but it's the 1st real week of practice--last 2 weeks have been under 3000yards all drill work and slow sets, and she's already icing 2x a day and has been since last week. I just hope she doesn't rip something because bottom line is sometimes when you do have shoulder issues you just need to back off a bit and concentrate more on form and legs instead of being the hero at practice, thats more or less why I have been so busy with extra curricular athletics because I know I can't go out there and swim meet pace every practice and still have shoulders to speak of.