I was treating at the Ironman in Penticton in August and being there is always an experience. Essentially, the meat of it is that in 30 degree celcius temperature, 2800 people or so swam 3.8 km, rode 180 km and 42.2 Km run. To regular Joe and Joettes like that, this seems inconceivable, but to an Ironman/woman, this is the result of training, often from short runs, to 10 km, to half marathons, full marathons, half thiathlons, full triathlons to the Ironman races. We worked with the athletes for the days upcoming with preparations to help them to get ready then helping them after the race.
A significant part of all this was helping them was just after the race when they came in. Many of them were so tired that they had trouble getting on the table. The treatments were mostly limited to flushing out the muscles and helping to bring blood to the muscles to aid in repair and reducing pain. Many of them wanted to lay down to rest after but my suggestion to them was, if they were able to, to go down to the lake and move about in the water. The best thing that you can do after heavy exercises, whether it be running/biking/swimming or a weight workout, I have found that a good cool down with low intensity exercises or movements. Moving about in the water allows the body to move circulation around better and helps it get rid of Lactic Acid and CO2, which is a cause of Delayed Muscle Soreness, that you feel a day or two after. Essentially, muscles short contraction and lengthening from simple movement provides the pump necessary to bring in circulation. Shortening brings in the blood, drops off the oxygen, picks up the carbon dioxide (waste byproducts), then lengthening pumps out the CO2 rich blood out to the lungs to be breathed out.
When I do a long bike ride, I ensure that I spend 5 minutes at low intensity high reps before stopping my bike ride and I have noticed that the day after I am much less sore and noticed less fatigue, that allowed me to go biking the day after.
Another thing that I do, of course is an Epsom Salt Bath, which floods my muscles with magnesium, that in turn, remove calcium from the muscle cells allowing them to relax. Take a look at a good movie explanation at http://www.youtube.com/watch?v=5guQwhRhV60