Hey, I'm down! Great idea!

In my case, I'm just not very active during the winter months, and even during the summer I sometimes have a hard time making it to the gym. I've just started daily running again recently, and that's something I want to keep up on, in addition to summertime activities, like hiking and such. I guess my incentive is not so much the con as it is my wedding next month, but the reason I'm working on it is just because there's a higher quality of life when you're healthy and active. And besides that, all girls deserve to be delighted when they look in the mirror. ♥
Currently I weigh 120 lbs, but I'd like to drop a few fatty pounds and develop the muscle pounds. I'm not precisely sure of where my weight levels off, but I'm mostly just concerned with being healthy and lean. So... I guess it's not that dramatic, but constantly staying in shape through a healthy lifestyle takes a lot of commitment!
For myself, I'm mostly trying to jog for 30 minutes every day and to do some kind of resistance training every other day. Especially for ladies, resistance training is important--we can't bulk up on huge muscles, but it can help us be strong and delay the effects of osteoporosis later in life--health is rather more important than just looking skinny.
As for healthy foods, I have a suggestion: Most advertised "health" foods are garbage, but foods that are naturally healthy are delicious! And summer is the best time to get them cheap. Go for whole grains, olive oil instead of canola, and hit up the produce section! Instead of a greasy, fatty dessert, treat yourself to some blueberries or watermelon. Experiment with different salads (but go easy on the dressing!). Take advantage of all the fresh fruits and vegetables that are on sale and look up recipes to use them in a variety of ways.
Now, in the summertime, is absolutely the best time to start!
And to Lusha--props.

Starting a healthy lifestyle is all about choices. Choosing a food that will satisfy you without stacking on the pounds, like a light frozen yogurt instead of ice cream, or a bagel instead of chocolate cake. Walking instead of taking the car, taking the stairs instead of the elevator. It'll all add up, and most importantly, it'll get you in the habit of making really good choices that will affect your entire life.