Advanced IIP Coach and 2:48 marathon runner Tia Accetta (Randy’s wife) pushes some athletes harder. This sequence for experienced runners keeps volume steady for three weeks while the intervals get shorter and faster. Then, runners return to a longer version of the original workout.
5 x 1 mile a little faster than your marathon pace, with one minute of recovery
10 x 800m at your tempo pace, with two to three minutes of recovery
20 x 400m a little faster than your tempo pace, with 200m of recovery
6 x 1 mile a little faster than your marathon pace, with one minute of recovery