What are you waiting for? Thinking about applying for the CNN Fit Nation team but apprehensive that you don't have what it takes? Do you find the application process daunting? Or are you waiting until the last minute to perfect your entry? Here is my advice to help you change your life:

1. Think you don't have the time? Think again. There will never be the absolute right time - all of us have busy lives that make the idea of fitting biking, swimming, and running workouts in our schedule daunting. Trust me, the time is there, and you will be surprised on how much there is once you find it.

If Dr. Sanjay Gupta can perform brain surgeries on Mondays, film a weekly television show, pinch-hit for Anderson Cooper and Piers Morgan, and raise three beautiful daughters, while finding time to fit the workouts in, so can you. If I could find the time while working full-time, raising twin girls, advising my yearbook staff and planning a wedding, so can you. The training will give you the energy to approach life with renewed vigor.

2. Scared about the workouts? Before this challenge, I had never run more than a mile at a time. Okay, I did once, in college, but that's it. My first 5K took me almost 39 minutes. But by following the plan my trainer set out for me, by the summer of 2012 I was running four miles at a time with ease. At the beginning of the challenge, swimming one 25-meter length of the pool left me winded. I collapsed in tears during kick off weekend, thinking I could never complete the triathlon using the front crawl. But, again, by following the plan that was set out for me, I now can swim 64 lengths of the pool in front crawl effortlessly. It won't happen overnight, but if you trust the plan that your trainer gives you, it will come.

3. Think your essay will be so compelling a video entry doesn't matter? For the love of all things holy, submit a video. As I have been reviewing each entry that has been submitted, I cringe for all of those who failed to upload a video because you won't be chosen without it. Even if you have to stop at Walmart hours before the deadline and use a shaky webcam like my good friend Glenn did, use something to record the authentic you.

If you can enlist the help of a tech-savvy friend (I was fortunate to have a student who had a talent for video editing), do it. The producers at CNN screening your entries are looking for stories to share. They are looking for people whom viewers of "Sanjay Gupta MD" can relate to. This isn't the time to be modest. Speak from the heart. Tell the CNN producers why you need this program to help change your life.

The group that will be chosen can expect their lives to change in unimaginable ways. I thought it would just be about losing 50 pounds and changing my appearance; I had no idea it would change my relationship with my husband and give us something new to look forward to in our lives.

Now is your time to change your life. The odds are in your favor. You have so much to gain and nothing to lose.

Best of luck, and I look forward to meeting the new CNN Fit Nation team in Malibu next September!