What should you do for recovery between hard workouts and races? The science behind routine easy days is sketchy, so here are my thoughts based on personal experience.
NO ACTIVITY: Complete rest is a good idea following something as strenuous as a marathon, or even a half if you have severe leg soreness. I usually wait up to 5-6 days before resuming normal activity, although there is nothing wrong with some easy cycling or swimming.
EASY 30 MIN: Pretty standard the day following up a hard workout or the day prior to a race. If it's pre-race, throw in 4-6 race pace strides after you finish.
EASY 60 MIN: Depends on your level of fitness, but some runners can use a longer easy day and still perform a hard interval or tempo session the following day. It's trial and error on what you can get away with. I would not use this before a race, however.
EASY 10 MIN/ 1 x 800 meter hard / EASY 10 min: I've used this prior to my last few marathons. Here is why.
CROSS TRAIN: I would bike or swim the day before or following long run workouts, but not before races. You could do some higher intensity work such as hills or a spin class or just go easy.
EASY 10 MIN/ 3-5 MIN RACE PACE / EASY 10 MIN: I have no reason to believe this works other than giving you peace of mind and a final reminder what race pace feels like. The shorter your race, the faster your pace on this for a shorter distance.