This is a workout designed to boost your top end speed and 400M time, which will translate into faster speeds across all distances. There is a very strong correlation between a runner's maximal 400M time and their marathon time.

To start with, warm up thoroughly with a series of strides at 90% of max effort for approximately 20-30M along with plenty of easy running and any other drills you favour.

For this workout you will need an area roughly 100M in length, a football field works well. If you use a running track, try not to stop dramatically in the middle of lane 1.

Start running your first 100M, using the first 20M to get up to speed, then hold onto your close to maximal speed it for the last 80M. Worry less about perfect pacing here, and focus more on top end speed coupled with good form at all times. Stand upright, look forward, and make sure you get a good stride length while still ensuring your foot lands underneath your body.

After your first 100M jog/walk for a 10 second recovery, then repeat by blasting off in the opposite direction. Repeat this for eight reps unless the pre-activity comments indicate otherwise.

This session will have a low TSS score, but is incredibly productive.