my calves ache after standing for several hours. i'm a cashier, so i'm really used to standing. this has only started recently. also, i wake up with cramps in my calves in the middle of the night, when i turn over. i switched my salt to 1/2 salt about 2 months ago. i increased my calcium from 600mg to 1200mg about a week ago. i also take a multi w/minerals. any ideas what else i can do? i walk 30-45 minutes a day and i work out with weights, so it's not from being sedentary.