Aside from an all-out-fast-as-you-can run for 15 minutes or so, which forms of cardio produce the most calories burned in a given amount of time.
I'm sure I could look this up but I think it would be neat to get the info on the board so people could see it.
Things im considering:
Jumping jacks - full body movement, if you "squat" on the way down you can really get some burn going.
Jump rope - Again, full body and you can get your arms going pretty good.
Up-Downs - Umm...hard to explain, tough to do more than 10 or 20 if you've never tried them. Basically you start at standing, jump straight down into a pushup and then throw yourself back up.
Any ideas for some high intensity cardio that doesn't involve the treadmill or running?