Last updated: Mar 30, 2016

You've got to admire Tracy Anderson. Once overweight—she put on 60 pounds during her first pregnancy, in 1999—Tracy knows firsthand the amount of hard work it takes to reshape a body. Her struggle to not only lose the pounds but get strong and sculpted as well became the blueprint for her 17-year-old fitness program, the Tracy Anderson Method.

These days, the Indiana native's series of ever-changing moves meant to target small (or, as Tracy calls them, "accessory") muscles for a sleek, chiseled silhouette has a cult following. Gwyneth Paltrow is a friend and partner, and J.Lo and Lena Dunham are just two of her many famous clients. But Tracy—who has expanded her empire into streaming video and is debuting a line of bars and shake mixes at Target this month—doesn't think of herself as an elite trainer. In fact, her favorite part of her job is working with regular women and getting them to really push themselves to achieve a body they never thought imaginable. (Her devotees have created #TAMily, a social media sisterhood that extends across the globe.) Now, teaming up with Health to lead the exclusive 30-Day Core Challenge: Transform Your Butt, Back, & Abs, Tracy is helping all of us do the same thing.

Her goal: to empower women to see our beauty, no matter our weight or body type. Over a salmon dinner in New York City's hip Tribeca neighborhood, the 41-year-old mother of two (son Sam is 17; daughter Penelope is 3) shares the genius advice Gwyneth gave her and reveals what strong looks like in 2016.

RELATED: Meet Tracy Anderson at Health's Total Wellness Weekend

What is the one thing that people neglect to factor in when it comes to exercise?
Strategy. Your workout is a focused amount of time that helps connect your mind and your body and pushes your health forward. It's about taking into account where you are—"I'm holding extra weight in my stomach," or "I'm having a hard time taking a deep breath"—and then deciding what you're going to do about it.

How important is the brain to workout success?
Keeping your mind engaged is key. Period. A good marker: If you can make your grocery list while you're working out, you're not engaged. And if that is the case, then you're not burning and sculpting as much as you potentially could.

People say change doesn't come until you push past your comfort zone, but that isn't as easy as it sounds.
Endurance athletes all have this moment when they enter this thing called the pain cave. Maybe it occurs on the last mile or when the weather becomes really bad and their ability to perform becomes really tough. When they get into the pain cave, they literally tell themselves, "I'm aware that I'm in pain, I'm aware that this is uncomfortable, but this will not last forever." They're trained to mentally become that strong because that is what it takes for them to achieve.

Are you saying that we're too comfortable?
We are wrapped in bubble wrap. We think that making it through the pain cave is putting our workout gear on and getting to class. Now, I'm not knocking any level of showing up, but I think many people are stuck in preschool with their bodies. Going for a walk is like going to preschool—but you could go to college, you could get your master's degree.

RELATED: 4 Exercises for Flat Abs and Trim Hips with Tracy Anderson

Is there an age when it's too late to get in shape?
It's never too late to show up for your health. You can be in the best shape of your life at any age. Now, if you're 50 and say, "I want to do all the things to look like I did at 30," well, that's an unattainable goal.

Is there one healthy food that you think everyone should have in their diet?
One food? How about one color? Green. Your diet should predominately be green.

That makes us wonder: Is there ever a time when Tracy Anderson falls off the eating-healthy wagon?
I just can't eat lean protein and vegetables every day of the month. I love French fries, I love pasta, I love food—there's not a potato that I do not love.

You're saying that it's OK to give in to your cravings sometimes?
Yes, but you have to know when to stop yourself, when to tap into that healthy fear that says, "If I have another milkshake, I'm afraid that will be unhealthy for me—for getting diabetes or for causing weight gain." When you lose a sense of healthy fear, then you become reckless, and that's never healthy.

You and Gwyneth Paltrow have been close pals for years. Is there anything you've learned from her that you've taken to heart?
She shared with me that her father once told her that when someone shows you who they are, believe them. Don't try to justify the times they were great, because the times when they weren't is who they really are.

RELATED: 4 Steps to Sleek, Sculpted Arms with Tracy Anderson

You've worked with so many powerful women, from CEOs to celebrities: Have you noticed a mind shift in what influential women want their bodies to look like?
Women are tired of being sold youth to an unhealthy extreme. They are tired of model-like women being dangled in their faces. They are fighting against the idea that they have to be a 19-year-old child to be beautiful. Women are now saying, "Hey, I can be 50 and beautiful!"

So when will we stop hating on ourselves?
When we give ourselves permission to celebrate our own beauty. It's one reason why I love Lena Dunham as a client. Her objective is not to become a size 2. It's to feel more connected to herself and to feel healthier and be balanced in her life. If she wants to have pizza with her boyfriend, then she's going to have pizza with her boyfriend. She's not in a race to be something that she's not, and that's one of the things that make her so beautiful.

Are you up for Tracy's challenge? Get started here: 30-Day Core Challenge: Transform Your Butt, Back, & Abs

As told to Rozalynn S. Frazier