Had that, really sucks, especially in the morning. Like everybody said stretching is key. I would put the ball of my foot on the front door sill and drop my heel, gives a very good stretch and helped a lot. Lots of good info on the net for how to deal.
In your helmet, no one can hear you scream.
Old(ish) Chick on a Bike
V-Strom 650 Adventure "Maxwell"
DR-Z400s "Little Donkey2"