Fitness and Speed Endurance Training for Sprinters
Here we are going to break the fitness needed for sprinting into two distinct categories.
Firstly, you need to get a good level of general fitness or conditioning done in order to be able to do the more specific sprint work, without undue risk of injury or illness and in order to be able to do this training over a period of time.
Secondly, we'll look at speed endurance, which is the maintainence of a high level of speed over the duration of a race.
This is achieved by a degree of aerobic work, concentrated early in the winter (from about Sept - Nov) for those wishing to compete well during the summer.
Activities such as circuit training and steady running (generally of no more than 3 miles, but at a reasonable speed) are important and generally used by athletes. However, it is also perfectly reasonable to get this sort of fitness from cross training, eg. a game of squash, cycling, a game of football etc, so long as the injury risks associated with these are recognised.
As mentionned, this work is generally done early in the year, but should be maintained at a lower level throughout the training year.
The key to winning any sprint race - isn't necessarily having great outright speed, although this is obviously very useful! The key is maintaining as near to your top speed as possible throughout the endurance of the race.
No-one can sprint 100% flat out for more than about 20-30m - therefore you need to learn to run at just below top speed for distances longer than this. The key is staying relaxed and avoiding tension in your muscles, whilst still running very fast.
The primary way of practicing speed endurance is simply to run distances of between about 80m and 250m with significant recoveries (at least 4-5 minutes for each 100m just run) and maintain a good speed for the whole run. If you are tying up towards the ends of these runs, concentrate on relaxation and maintaining cadence (it is okay to sacrifice your stride length slightly as you get tired).
The next way to practice speed endurance is through using "in and outs". These are reps, which are split into alternating sections where you concentrate on speed and relaxation. A run of 100m is good for this, with 15-20m sections for the speed and relaxation. This is good for advanced runners - it helps to reduce these intervals to about 10m for less experienced athletes.