When it comes to working out, I definitely prefer cardio to weights. Don't get me wrong, I do the weights, they're just not my favourite. I prefer to pop in my headphone, blare the tunes on my iPod and run my worries away on the treadmill. Yes, weights are important, but cardio is also important, so don't feel bad if you're a fellow cardio junky -- it's definitely one of the better habits to have.

There are plenty of ways to get your cardio in, but the most popular cardio exercises at the gym seem to revolve around the treadmill, the elliptical trainer, the stationary bike, the recumbent bike and the Stairmaster. Which one do you love the most? Or at least tolerate the most?I recently saw this article on Women's Health (via Fitsugar) on the best cardio exercises for your butt. That is, they measured how much of your glute muscles each exercise uses. The verdict? Jogging on the treadmill is the best cardio for your booty because it uses 49% of your glute muscles. Then there's the elliptical trainer at 34%, walking on the treadmill at 24%, the StairMaster at 24% and the recumbent bike at 6%.

They also have some tips for maximizing your tush toning:

• When running on the treadmill, be sure that your heel hits the surface first, not the ball of your foot.
  
• When walking, add an incline, and/or walk sideways or backwards.
  
• On the elliptical, stick your butt out and dig your heel into the peddles (yes, you'll look funny but you'll be the one laughing when you see results.)
  
• When biking, use the upright stationary bike instead of the recumbent one.
  
• On the StairMaster, stick your butt out a bit and take larger steps. On the real stairs, take them two at a time.
  

As for calories, here's a list of the amount of calories each of the below burns in a 150-lb person during a 30-minute workout according to this handy calculator from AOL Body:

• Stationary bike, moderate effort: 239
• Stair climbing: 307
• Aerobic dancing: 221
• Running, 9 minutes per mile: 375
• Brisk walking on a firm surface: 130

So it looks like running is a winner when it comes to helping you work your muscles and burn calories. But that doesn't mean it's the best form of cardio. Want to know what the true best cardio is?

It's the cardio that you like, the cardio that you find yourself able to do again and again. So whether it's running, walking, dancing, swimming, kickboxing or sweatin' to the oldies, the best cardio is the one that works ... for you!