Sleep

Sleep is when your body repairs muscle and absorbs training: most runners need 7 to 9 hours a night, more in heavy weeks.

• Most growth hormone is released in deep sleep; short nights lower endurance, make efforts feel harder and raise injury risk.
• Keep regular hours, a dark, cool room (around 16 to 19 °C) and no screens for the last 30 to 60 minutes.
• A 20 to 30-minute nap, no later than early afternoon, helps without spoiling the night; avoid caffeine in the 6 hours before bed.
• Before a race, a restless last night costs little: the nights of the week before matter most.

Short on sleep? Keep the day’s session easy rather than cutting sleep for an early hard one.