This interval session is a variation of the typical 400m training session.
The difference here is that we use decreasing recovery time interval to enhance the training effect on the body’s ability to run at higher intensities.
The session is split into 2 parts with a longer 4 minute recovery between each part. The reps (the 400m effort segments of the session) should be run at around 5k race pace or slightly faster. The recoveries are short and get even shorter, so the session detail looks like this:
- 5 x 400m at 3k-5k race pace with recoveries of: 90, 60, 30, 15 seconds
- 4 min very easy jogging recovery
- Repeat 1 & 2
The recoveries are active, but easy, i.e. not just standing or sitting but light jogging.
What this session does
Interval and repetition training is widely recognised as being very effective for running speed development, i.e. boosting endurance running performance capability.
This particular session specifically targets the body’s ability to clear lactic acid from muscles and to increase running velocity at lactate threshold. Lactate threshold velocity has been shown to be a key determinant of running fitness and performance potential.
Furthermore, the decreasing recoveries of this session get the runner used to running at high intensities without much recovery; of course the extreme example of this is a race, where no recovery is taken at all.
The 15 second recoveries will seemingly pass in an instant, but they do a remarkable jog of demonstrating that we can still continue to run at high speed even when we feel pretty exhausted. Once a runner has a grasp of this and is familiar with that feeling, they begin to question the validity of the usual indications to slow down; that’s pretty potent mental strength to have on race day.
In a group of mixed abilities runners this session is easier to manage if it is based on time, so that the 400m rep becomes a 90 second rep (dependent on standard of athletes). Another useful point to help keep the group more ‘together’ is to change direction after each effort.