Generally defined, speed work is shorter repetitions, usually 800m or less, with a rest interval that allows the body to nearly completely recover from the previous repetition. This usually means that the rest will be at least two times as long as the time it takes to do the repetition. The important part of this equation is the recovery of the body; without that recovery speed work will not stress the proper energy systems in your body. Runners use a mix of aerobic (requiring oxygen) and anaerobic (not requiring oxygen) energy systems to propel us forward during a race. The shorter the distance, the more the body leans on its anaerobic energy systems.

Marathons require almost no contribution from anaerobic energy systems, a 10K requires only about 5%, a 5K 10%, and only when we get to the 800m and below do we see the body getting more than 50% of its energy from anaerobic sources. True speed work stresses those anaerobic systems, the body then adapts to this stress by learning to produce energy anaerobically efficiently and effectively. As you can see, most of your training should be devoted to aerobic work with speed work representing the icing on the cake.

How much and when you do your speed work, depends on the distance you are racing. We all love to run fast, and speed work makes us feel faster. That is why as runners we develop a psychological dependency on speed work, even though physiologically its importance is not nearly so great. When looking at the most popular race distances of 5K and 10K, the amount of speed work needed is relatively little and occurs late in your training program. Its use is much like switching from training shoes to racing flats for a race, part mental and part physical.

Three to four speed workouts in the month (or about 1 a week) leading up to your chosen 5K or 10K should be enough to have you properly tuned up. Earlier on in your training program you can do hill repeats and workouts such as repeating eight to twelve times 200m (meters) at a little faster than 5K pace with a 200m jog to get your body warmed up to the idea of true speed work.

When you do get to this last month, here are some workouts that are great for squeezing that last little bit of fitness for your race. You can also use these workouts to training for shorter races too.

Some of my favorite speed workouts are as follows:

100m, 200m, 300m, 400m - three sets:

8 x 300m accelerations:

4 x 800m:

6 x 400m:

When doing a speed workout remember it is crucial to warm up properly. An easy 15 minute to 20 minute jog, followed by light stretching and strides will help to keep you healthy. Remember to choose your paces carefully so you can finish the workout as strongly as your start it, ideally your fastest interval should be your last. Focus on getting enough rest between intervals to allow recovery but not so much time you get stiff. Make sure to cool down properly with another 15 to 20 minutes of easy running.

To summarize, use speed work at the end of you training program to help get that little bit of turnover you need to get those last few seconds off you time. Use hills and some lighter turnover drills, such as the 200's described above, early on to get you legs used to moving fast before you do true speed work. When you do speed work make sure to warm up and cool down properly to avoid injury. Finally choose an initial pace that you can handle and work into the workout with your fastest running at the end - just like in your next race.