04 The 5-Minute Mile
The point Running 10K won’t get you anywhere. According to UK Athletics coach Frank Horwill, one mile is the optimum distance for improving speed and endurance. That’s because only half of the oxygen required can be inhaled, making this a half-aerobic and half-anaerobic sprint to the finish. The plan A mile might not feel that far, but breaking it down into smaller sections will help you go the distance. “Practise 400m first, aiming to complete the distance in 50 seconds. Once you’ve got that, try 800m, aiming to finish at around one minute 50 seconds,” says Whitelock. Double the time allowance as you work up to 1600m (one mile) for a cardio kick that won’t kill muscle growth.