Why it matters

The Interval Run builds your aerobic base, work capacity and conditioning.

How to do it

Warm up thoroughly before the first hard effort.
Set your effort to a pace you can sustain for the planned duration.
Settle into a rhythm before pushing the pace.
Hold a steady, repeatable rhythm for the working duration.
Keep your breathing matched to your pace throughout.
Adjust your effort so the last minute feels as controlled as the first.
Run each repetition at the assigned effort and take the full recovery between them.

The recovery is part of the session — cutting it short turns the whole thing into a moderate run.
Settle into a cadence you can hold for the full effort.
Breathe rhythmically and in time with your pace.
Build the pace gradually rather than starting too hard.
Run tall with a quick, light cadence and relaxed shoulders and hands.

Starting the first repetition faster than you can repeat.

This takes work off the target muscle and reduces what you get from the set.

Instead Set the pace you could hold for the last rep and start there.
Starting too fast and fading in the second half.

A fast start you cannot hold means the back half of the effort suffers.

Instead Open at a pace you could hold to the end, then build.
Tensing the shoulders and upper body while working.

Tension up top wastes energy that should go into your legs and lungs.

Instead Relax your hands, shoulders and face so the effort stays in your legs and lungs.
Letting the effort drift down whenever your attention wanders.

Coasting drops the training effect for that stretch of the effort.

Instead Check your pace regularly and hold it steady to the end.

Tempo: Hold a sustainable, repeatable pace for the target duration.
Breathing: Breathe in a steady rhythm matched to your cadence.
If you are new to it: Use intervals of easier effort to build duration over time.
Once it is easy: Add pace changes or intervals to raise the training stimulus.