Exercise for Cabin Fever part 1: Ideas?

Playing outdoors as much as possible is so important for children. The sunshine, the feel and sound of nature, and of course the physical activity. So hello scarves mittens hats boots and many many layers. Hello umbrellas and boots and raincoats. I'm really thankful we have such gear so my son can comfortably explore and exercise in various weather.

Whether it's because the weather is so bad it's unwise to play outside, or there's illness, or the schedule, some days the family is stuck indoors. Maybe for several days in a row. Everyone develops cabin fever. Especially toddler. That three year old just wants to run and climb.

I'm sure, if you've worked with kids before, have kids,  or remember your own childhood,  you've seen a preschooler with cabin fever. We all need that daily sunshine and exercise. Who can really blame them?

So what do you keep on hand for such times? Do you play indoor sports,  reach for a book of physical activity ideas, or have some preschool exercise DVD you and your child enjoy?