Most traditionalists say that you should not do speed work on a year-round basis. The rationale for this is that your body and especially the nervous system, cannot handle the stress of speed work on a year-round basis. In this they are correct. But the answer is too simplistic.
Speed work should be done on a year-round basis but not to the same extent. The amount of speed work is determined by the objective which in turn is determined by the generally accepted periodization plan. Thus the amount of speed work in the off-season is low but still maintained so that you do not lose what was gained during the season.
Only in this way can you show appreciable improvement from year to year. If you completely eliminate speed work in the off-season, you’ll waste too much time building up to where you can begin speed work in earnest prior to and during the competitive season. This does not allow for much improvement in your performance.
This is a very important point to keep in mind. You should never build up to a high peak in one season and then lose it in the off-season only to build up again for the new season. This is what traditionally has been practiced in track and field. After the competitive season, sprinters and middle distance runners would do cross country running for base training prior to beginning training for speed once again in the track season.
But if you perform a very small amount of speed training during the off-season, it will allow you to maintain your speed without the stress experienced by doing challenging speed track workouts prior to the upcoming race season. Most important here is that you will be able to increase your speed even more by maintaining speed work throughout the year.
This concept applies not only to track athletes but also to all athletes who do considerable running in their sport. This includes football, baseball, soccer, lacrosse, tennis and other team and dual sports. However, this concept has not been widely accepted by coaches in all of these sports. As a result we still see many athletes going by the outdated traditional periodization plan.
It should also be noted that in the off-season you should not do any overspeed training. It should be reserved for the precompetitive and competitive periods. Having a short speed workout once or twice a week is usually sufficient to maintain nervous system memory. It should however, precede any strength or explosive training that is done in the workout.