While many people may want to increase their muscle mass primarily to improve physical fitness, some are also after a more attractive physique.

Glutes, triceps, obliques and chest muscles are all desired. Biceps are, too. But often the most buzzed about muscle region that people are after is abdominal muscles. Men in particular frequently chase the chiseled six-pack, only to find that getting it is easier said than done.

Here's what the health and fitness pros say about the overall benefits of building a strong core, plus which exercises are most likely to yield your desired outcome.

Are abs a sign of good health?  

Though defined abdominal muscles aren't necessarily a definitive sign of overall good health (for some people, an obsession with a lean stomach can lead to or stem from an overly restrictive diet), having strong abs usually means achieving a level of physical fitness that benefits the whole body. 

That's especially likely because plenty of cardio often accompanies ab-toning workouts; and abs are only one part of the body’s core muscle group that are affected by abdominal exercise. "Many people overemphasize the importance of abs, which are important, but they are just one part of our overall core," says Dr. Shelby Johnson, a physical medicine and rehabilitation specialist at Mayo Clinic, Rochester.

Austin "Ozzie" Gontang, a licensed psychotherapist at Pacific Pearl of La Jolla and the director of the San Diego Marathon Clinic, agrees. He says that core muscles are fundamental to "maintaining good posture, preventing injuries, and enhancing overall physical performance." These core muscles include the internal and external obliques, the transverse abdominis ("the deepest abdominal muscle which wraps around the spine," Gontang says), the erector spinae, pelvic floor muscles (which form the base of the core), the diaphragm, gluteus muscles, and the rectus abdominis - "the muscle at the front of the abdomen that most people think of as the 'six-pack,'" says Gontang. 

"Each one of these muscles must work together to enhance the stability of the spine," explains Dr. Michael Fredericson, director of Physical Medicine and Rehabilitation and the co-director on Longevity at Stanford Medicine. He says these muscles are also important for improving breathing, aiding everyday movement, and are essential for providing balance and support. 

Is it hard to get abs?

As for actually strengthening these muscles and getting noticeably stronger abs, it's important to remember that a healthy diet usually needs to come first. "The old adage 'abs are made in the kitchen,' underscores the importance of nutrition in achieving a defined abdominal area," says Gontang. He explains that overall visibility of one's abs is "heavily influenced by body fat percentage;" so one must avoid fatty foods, be mindful of calories, and get plenty of healthy nutrients to maintain a healthy enough body for abdominal muscles to be visible.

After all, as Fredericson points out, getting abs isn't the objective "since we all have abs already." Rather, it's about having the kind of physique where abs can be seen, then activating and defining that group of muscles by making them stronger.

Beyond diet, other factors affect whether one's abs become readily visible. "Genetics play a role in how abs develop and appear," says Gontang. Different exercises and approaches will also lead to varying results in different people. "It's important to remember that no single exercise regimen works for everyone," he says. "The best results often come from a varied workout plan that keeps the body challenged."