By Anne Fisher, contributor

2011 is less than two weeks old, but you may already be struggling to stick with your plans to shed a few pounds, get organized, or embark on the search for a better job. If so, you’re not alone: New Year’s resolutions seem made to be broken, with 49% of Americans admitting in one recent survey that their 2010 vows resulted in “no change.”

That’s partly because we tend to be ambivalent toward our own goals, says David Kaiser, CEO of Chicago-based executive coaching firm Dark Matter Consulting, who describes his mission as “helping leaders become bigger than the problems they are currently stuck in.”

“Every person is like a committee whose members bicker among themselves. So when you try to make a change, part of you is completely on board with it, and part of you isn’t,” Kaiser says.

Often, the nays have it, because “there is almost always a payoff for not changing,” Kaiser adds. “The key is to figure out what that payoff is and find a different way to get it, or to get a different payoff that’s just as good or better.”

Sure, it’s more fun to surf the web than to launch what may be a difficult, discouraging job search, for example, “but you can overcome that by picturing in detail what you would love about having a new job. Once you find a real, heartfelt reason for doing the work involved in getting there, you find the energy to do it,” says Kaiser.

Moreover, many people avoid change because of unwelcome emotions that come with it. As the late John Updike once said, “All change is loss. There is no other way.”

Abandoning the familiarity of the job you have now, for instance, might feel more threatening than you like to acknowledge. “Accept that fear and keep going,” Kaiser advises. “It’s only a feeling, and feelings are never fatal.”

Think you may have set a goal for the New Year that is a tad too ambitious? An impressive body of neurologic research suggests that, on the contrary, your goals may not be challenging enough, according to Hard Goals: The Secret to Getting from Where You Are to Where You Want to Be.

“The more difficult the goal, the better your performance will be,” writes author Mark Murphy, who is the CEO of Leadership IQ, a research and management training firm based in Washington, D.C., that includes IBM (IBM), Microsoft (IBM), Merck (MRK), and MasterCard (MA) among its clients.

Why? Tough goals “force us to pay attention,” Murphy writes, despite the daily bombardment of distractions we all face. He quotes molecular biologist and brain researcher John Medina: “The more the brain pays attention to a given stimulus, the more elaborately the information will be encoded.”

By these lights, an objective that “puts you right in the sweet spot of difficulty,” Murphy says, requires you to learn: “It’s going to stretch your brain, excite some neurons, amp you up, and awaken your senses. If you can breeze through it without learning anything, your goal is just not difficult enough” to call forth the brainpower that will keep you committed to it.

What if you’ve made a New Year’s resolution that you suspect isn’t going to stretch your current skills, teach you some new ones, engage your imagination, and get you all fired up? There’s just one solution, Murphy says: Set the bar 30% higher.