Let us consider a few 10k race goal times:
|10k race time||Pace/400m (secs)||Speed reserve test aim|
The above examples give a speed reserve of 6 to 8 seconds which is good. If the above times in the test had been respectively 74, 94 and 118 seconds there would be a problem because your speed reserve is too close to your actual race pace.So the aim is to learn to run faster (while relaxed) in the interval workouts. Speed reserve should become a high training priority as you prepare for a target 10k race.