GREENWOOD VILLAGE, Colo. -- For many people with the goal of getting in shape in living healthier lives, actually achieving those goals can be difficult.

The biggest obstacle is knowing where to begin, said Neil Cestra, owner of Essential Fitness in Greenwood Village.

"When someone joins Essential Fitness, we first do a body age assessment, so we determine their current state of health," Cestra said.

The Real Body Age test is a detailed assessment that is based on statistics. It screens a person for five different types of cancer, cardiovascular disease risk and Type 2 diabetes. The test takes into account your family history, lifestyle, flexibility and strength.

"The people who aren't healthy and get a very high body age are doing things we know not to be the best habits," Cestra said. "The people who are healthy and have a good body age are doing the right things."

When David Croft took the test a year ago with his wife Nancy, he was 47 years old. David thought he was average when it came to being in shape.

The results came back, and the father of two young children was shocked. David had a body age of 64.

"It was really hard emotionally to sit and say to yourself, 'My gosh, I'm 64 years old inside,'" David said. "I have a 2- and a 4-year-old, so I need to change my life drastically if I'm going to be around."

Nancy had no idea her husband's body age would differ so much from his real age.

"I thought he was in better shape than that on the inside," Nancy explained. "I thought he had a little bit of weight to lose, but I didn't realize his body age was so drastically high."

Nancy's test results fared much better than David's. At the time of her first test, Nancy was 41 and her body was the age of a 34-year-old.

"I knew that I still had work to do after two young children. I knew I had to drop some weight," she said.

Nancy and David made a commitment to each other to change their lifestyles. The couple eats healthier, and they work out five days a week.

Nancy said it isn't always easy, but they find a way.

"We try and do a lot of cardio on our own because we find that's the easiest to do. David is able to work out at school as part of his day, and I get up early in the morning."

At Essential Fitness, Nancy and David get personal attention with their trainer three times a week. Cestra gives them encouragement and challenges. As their trainer, he's giving them guidance on how they can reach their goals.

"When you have a map and a blueprint and you know where you're going, that's how you get there," said Cestra. "If you have no idea, then you're just shooting in the dark."

After a year of lifestyle changes, it was time for Nancy and David to assess their progress.

Nancy had lowered her body age even more, and at the age of 42, her real body age is 31. Her trainer said she could still drop even more of her body age if she improved her strength from good to excellent.

In a year, David had lowered his cholesterol and had an overall heart disease risk of zero. David lost 18 pounds and took 20 years off his body age.

At the age of 48, David now has a body age of 44.

Cestra said lowering your body age doesn't necessarily mean you're going to live longer.

"It's not so much as a hocus-pocus type of thing where you're adding years to your life," Cestra explained. "Compared to other people, they are beating the odds... they are beating the average, so then you beat the life expectancy a little bit."

"You kind of put a skip in your step again," David said. "It's really fun."

Nancy said she couldn't believe how drastically David's body age dropped.

"By no means did I expect it to be 20 years difference. I'm thrilled because I want him around for a while," Nancy said.

For more information on Essential Fitness and the Real Body Test go to essentialfitdenver.com.