Sleep does half the work

Motor consolidation — the firming-up of newly learned movements — happens mainly during sleep. Those who sleep after a practice session improve their performance by 20–30% over those who stay awake. In deep sleep the brain runs through the movement sequences without the body stirring.

In practice that means: a short session shortly before sleep is especially valuable — fifteen minutes in the evening puts the whole night to work as training time. What it does not mean: sleep doesn't replace practice, it reinforces it. No practice, nothing to consolidate.