Pacing your hard and easy runs
According to most of the experts and professional coaches, most of us run our "easy runs" too hard, and our "hard runs" too easy. To counteract this try to run your weekly long runs at a pace that is one minute per kilometre slower than your usual or projected race pace. Then try to run your XS workouts at a pace that is slightly faster per kilometre than your projected race pace. This will also leave you with enough energy and strength to also do one weekly tempo run at race pace.