See more at: pinterest.com This challenge targets our most-mentioned "problem" areas: our butts, thighs, and abs. It starts off simple, but it escalates quickly.

See more at: pinterest.com All you need to sculpt your arms is three weeks and a set of hand weights (maybe 3 pounds in each hand).

See more at: pinterest.com Can you do 50 pushups? I can do about five. Do this challenge though, and in 30 says, you'll be doing 50 pushups. Wow!

See more at: pinterest.com I shudder to imagine how my legs would feel after 100 squats, but... I mean, I also imagine how good they would look, so it's worth it.

See more at: pinterest.com Am I saying you'll have Kim K's enviable butt in just three weeks? Well, no. But you will have a much more toned tushie, and that's even better.

See more at: pinterest.com Okay, I've tried that starfish-looking plank and I've fallen on my face. But I'm willing to try it again for this challenge... are you in?

See more at: pinterest.com Who doesn't want a better butt and stronger core? I know I do... so I'll give this challenge a try. It's only two weeks, right?

See more at: pinterest.com Remember a while ago when I said i thought 100 squats might end me? Well, this challenge ramps up to 200 squats. I may require medical assistance after, but I'll have an awesome butt.

See more at: pinterest.com I don't want to have a six-pack, really. I'd just settle for losing some of this muffin top. This challenge will def get it done. So... which one of these challenges do you want to try first? Or is there another challenge you're working on?