Across thirteen studies, time off reliably improved mood, stress and exhaustion. Then the first week back undid much of it, and within a few weeks the gains were mostly gone.
You can’t bank rest. If daily work drains people faster than evenings and weekends restore them, annual leave can’t make up the gap. Shorter, more frequent breaks — and work designs that allow recovery in the normal rhythm of the week — matter more than a generous leave policy.