I've heard different runners say to add some short strides at the end of an easy day to help add speed.
Does anyone add anything longer? Like 8 x 200m on/200m off, just to get your legs moving? I'm not talking about an all out sprint, but would that have a similar effect as strides?
Adding short strides at the end of your workout will make you more comfortable with increasing speed while tired, but it won't add to the fastest speed you could run.
An all out sprint with have very different effects from fast strides.
-The all out sprints will stimulate your Creatine Phosphate System used for the first 4 seconds of effort. You're best off doing those at the beginning of the workout to reduce the trauma to your joints and bones.
-The fast strides will make you more comfortable at speed and might stimulate your Anaerobic Glycolysis system used for 4 to 30 seconds of effort. They might also loosen you up a bit if you keep them shorter than 200m.
There is a lot of disagreement about when to do your speedwork, with many recommending to finish up your workout with something fast. I prefer to do it all at the beginning, knowing that the body tissues are already stressed at the end of a workout.
**8x200on/off would be a rather stressful workout by itself unless you ran it slower than mile pace.