Everyone you speak to has their own opinion about stretching, when you should stretch, how often and for how long. I make it a habit to never start a swim, bike or run session before doing at least some sort of stretching.
So when and what should you stretch....
Your range of motion (flexibility) will directly affect you performance in each discipline. If your back and arm muscles are tight then you won't be able to get your full range of motion from each stroke and as a result will not be as efficient in the water. The same can be said for the hamstring muscles. If they are tight then you will not be getting the best out of you cycling and running.
A lack of flexibility will have a direct result on your performance, your form and range of motion... Be sure to read some of our other posts on stretching techniques and examples of different stretches.
Sometimes Less Is More Over stretching is a big problem as you can end up doing some serious damage to yourself especially after a really intense workout where your muscles are already weak. You must listen to you body and make up your own mind of how much to stretch.
Before and After? It is my opinion that pre-workout stretching is just as important as post workout stretching. Some athletes and fitness guru's agree with this and some don't. Ultimately it is for you to make your own mind up as to what works best for YOU! Stretching before and after a core or weight workout also helps to maintain muscle continuity and flexibility.
What works for you?