Cara Kempf is a certified personal trainer with the Fitness Zone in Carmel and a group fitness instructor with NIFS in downtown Indianapolis. She can be contacted at fitnessblog@theindychannel.com.

I recently received another question from a student, wondering what her ideal body weight is for her height, as well as what she could do to tone up over Christmas break. Thanks for writing; here are some answers for you!

There are many ways to decide whether you are at your ideal body weight/body composition. Not only do you have to factor in height and frame size, but also the composition of the weight (how much is fat, how much is muscle). It is not uncommon for an exerciser to lose fat weight and gain muscle weight without much change in total body weight. You can figure out your body mass index, knowing that normal weight ranges between 18.5 and 24.9. Anything under 18.5 is underweight; anything over 24.9 is overweight and/or obese. Here is the formula:

BMI = (Weight / 2.2) / (Height in inches x 2.54 / 100)squared

In addition to figuring your BMI, you should have circumference and/or skinfold tests done by a fitness professional (let me know if you're ever in my area!). That way you will know how much of your body is fat, and how much is muscle, so that you can decide which diet and exercise plan will work best for you.

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As for your holiday workout plan, here are some tips:

Try not to overindulge in food while you're home from school. Treating yourself every once in a while is OK -- not every day!

If you have a month off (most college students do), then get to the gym -- you don't have homework, so it's the best time for you to get back in shape. If you don't have access to a gym, try places like Cardinal Fitness where you can pay for one month and not have to sign a yearlong contract.

If you don't want to join a gym, buy a couple of exercise videos and hit them hard every day until you go back -- then you can take them back to school with you!