A dedicated fitness regime can tighten those abs, tone your legs and give you sculpted arms. But there’s one thing it can’t do: Give you the body you weren’t naturally meant to have.

"Working out can definitely define your body," says Anne Barber, fitness coordinator at West Wood Health and Fitness in Pewaukee. "But can you redesign your body? Definitely not."

A good first step is to start with a trainer who can offer a thorough fitness evaluation.

"We do an extensive number of body measurements at our very first meeting," she says. "That helps us set some realistic goals. It can be hard when someone comes in with a photo and says, ‘That’s what I want to look like.’ If it’s not your body type, odds are we won’t be able to achieve it."

That dose of reality is important, agrees Mike Lederer, director of Fitness Recruiting/Training at the Wisconsin Athletic Club’s North Shore location.

"There are so many different body types out there," he says. "If a client doesn’t recognize his or her body type, than it is up to us as trainers to set some realistic goals based on that type."

In fact, your body’s natural structure often is a good place to start in deciding the most effective total workout. "People who tend to put on muscle really easily generally do better with higher-paced workouts with higher-rep sets than trying to use heavier weights," says Barber. "You can then mix in interval training to consistently burn calories.

In contrast, lean people who are seeking to build muscle mass will want to try the opposite approach.

"In this case, we will typically suggest heavier weights with lower repetitions," she says.

Equipment choice is also a factor in performing the right kind of workout for your body type, and whether or not you’re training is aerobic or anaerobic.

"Incorporating kettlebells — which are a very old school style of training — is a very anaerobic approach, so it’s intense," says Lederer, as an example. "But for someone who is looking for moderate intensity, including some treadmill work will be helpful."

Working within your body type means improving on what nature and genetics have given you.

"We all have areas of our bodies we don’t like," says Barber. "If you have heavier legs, we probably won’t be able to change that, but with the right workout, we can help you make them more defined and leaner. And on top of that, you can also improve on the parts of your body that you really do like and make them even better."