The research concluded that the key factors in boosting times for the mile (or the 1500 metres, if you prefer) were anaerobic power, V02max and running economy (the amount of energy needed to run at a quality pace).

How can you boost all three? It's simple if you use the following workouts. Sessions that build anaerobic power are marked with an A, those that boost economy are marked with an E, and those that upgrade V02max have a V (note that some workouts help both anaerobic power and economy):

(I) Sizzle through 400-metre intervals at close to top speed, with a recovery period (slow jogging) which lasts about two and one-half times as long as the actual interval (A).

(2) Run 400 metre intervals at a pace three seconds faster per 400 than current one-mile race tempo (or 800 metre intervals that are six seconds faster per 800), with eight-minute, slow walk recoveries in either case (E).

(3) Hill assaults: rocket up a steep, short hill (less than 75m high) at close to top speed (A & E) and recover by walking back down. If you live a flat section of the country, substitute stadium steps or a staircase in a tall building for the hill. Another possibility is to do 20-second repeats on a stair-stepping machine at a very high intensity, with two-minute recoveries.

(4) Hill climbs: find a more gradual hill with a longer upslope (200m or so) and repeatedly run up it. Half the time, run at close to mile pace, and the rest of the time 'bound' up the incline with high knee lifts and a springing action at the ankles. Recover by jogging back to the bottom of the hill (A & E).

(5) Aerobic intervals: run 1 200-metre intervals at a pace 25 seconds per 1200 slower than one-mile pace, with recoveries equal to or shorter than the intervals (V).

All the above workouts are high intensity, so slower running is reserved for warm-ups, recovery days, and the off-season, when it's fine to boost your mileage in an effort to aggrandize V02max.