We cannot emphasise enough the benefits of stretching before and after training sessions. In addition, the full body stretch shown left is well worth doing two or three times a week.
There is no doubt that careful dynamic stretching before starting both bike and run helps to prevent injury and gets the muscles warmed up quickly.
One of the major problems with running and cycling significant distances is that, while they both build muscle, those muscles do not go through their full range of movement. The consequence can be the development of large strong muscles that are tight and short. This puts extra strain on ligaments and tendons. Static stretching after training will help avoid this.
Swimming is different. Good stretching before your swim will help produce a better stroke but it is less necessary after the swim because the range of movement of the muscles is good. However, swimming well demands flexibility of all the joints involved - other words almost every one, so we have included a set of stretches you can do daily that will improve your stroke - and speed!