You want to make changes to your fitness, work habits, career or other aspects of your life in 2016. You know that the best way to make life changes is by changing your habits. Habit is an incredibly powerful force that dictates much of how we live our lives. But eliminating old habits is almost impossible, and creating new ones is almost as hard. You know because you've tried and failed. Multiple times.

According to Dr. Jason Selk, you've fallen victim to "fight-thrus." Selk is an executive coach who was formerly the St. Louis Cardinals' director of mental training--during which time the team won two World Series. He's the co-author with Tom Bartow of Organize Tomorrow Today: 8 Ways to Retrain Your Mind

Most habit formation begins with a triggering incident, Selk says. For instance, you feel out of shape, you attend a workshop on the benefits of fitness, and you decide to work out every day. You start out with a run on the first day, afterward you feel great, and you're confident that this will be your new routine. But on the third day, the weather turns rainy and it's a battle to get yourself out the door.

"At some point, obstacles will test your resolve and you'll have to decide if you're going to take the easy route--as most people do--and stop the routine, or go forward and win your fight-thru," Selk says. "Fight-thru is where your initial confidence morphs into the realization that winning is going to be harder than you ​thought. You need to be able to win two or three fight-thru battles with yourself to reach the point where a habit becomes second nature."

How do you win those fight-thrus? Here's Selk's advice:

1. Ritualize your new habit.

Do this by putting your new habit on your schedule, at the same time every day or week. "If the habit is taking a thirty-minute run every day, block it out on the calendar for the same time and make it nonnegotiable," Selk says. "This takes most of the thinking out of it. You're almost automating the process."

2. Recognize fight-thrus when you encounter them. 

When it's day three of your new running habit and you're debating with yourself whether to go out in the rain, begin by recognizing what's happening, Selk says. When this happens, learn to say to yourself: "I've entered a fight-thru."

How will this help? "This is like taking the blindfold off before the fight begins," he explains. "Now you know what you're fighting." Every fight-thru you win makes winning the next one easier, he says. The reverse is also true: Every fight-thru you lose makes it easier to give in next time.

3. Ask yourself two questions.

Now that you know what you're up against, you can coach yourself through the fight-thru by asking yourself two questions: "How will I feel if I win the fight-thru? And how will I feel if I lose it?"

"You're now bringing emotion into the equation, which promotes action," Selk says. "If in your mind you win, you may feel like a champion. If you lose, you'll probably experience negative emotions that come with underperforming. Negative or positive, these emotions are powerful motivators to help you win the fight."

4. Visualize your future life.

Spend 30 seconds thinking in detail about how your life will be different in five years if you consistently win the fight-thrus and form a new habit, Selk says. "Be honest with yourself, and let yourself feel the benefits of constantly winning the fight."

Then, do the same thing in the other direction. Spend 30 seconds thinking about your future life if you consistently lose the fight-thrus and stick with the status quo. "It's your choice," Selk says.

5. Don't get hung up on results.

Let's say you've been winning your fight-thrus for a while and you have successfully formed a new habit. Congratulations! But just because the habit is there doesn't mean it can't fall apart, so you must stay vigilant to protect it.

One common setback is when the new habit doesn't immediately deliver the results you were hoping for. "It's easy to slip into a negative mindset," Selk says. "'Why do I bother? It doesn't matter what I do.'" When this happens, you have met the Discouragement Monster, he says. "It's so dangerous because it saps your willingness to keep trying. Keep trying anyway; you will win."

6. Don't let disruption ruin your progress. 

Millions of people start diet and exercise routines in summer and they work for several months, Selk says. Then Thanksgiving arrives, followed by Christmas and the inevitable Christmas parties. "By January, you're back where you were in June," he says. 

The answer is to be vigilant, and avoid breaking your new habit whenever you can. "Any break in your routine, will disrupt the positive habits that brought you success," he says. "Be careful to protect your routine." 

7. Don't be seduced by success.

Tell me if this sounds familiar: You decide to get in shape by running every day. Then you hear about a 5k or 10k in your neighborhood, and you decide to enter. You keep up your running routine until the day of the race, which you successfully complete in a respectable time. You're thrilled--and then you stop running.

"Maybe the most dangerous trap comes when you have great success," Selk says. "You've won the fight-thrus, you've changed your pattern, and now you're feeling great. It's human nature to think, 'Hey, I've got this licked. Now I don't have to work as hard.'"

In other words, you've been seduced by success. "Recognizing seduction is an important part of avoiding it," he says. "Anytime you catch yourself saying, 'I can't do my tasks today because . . . ' or, 'I don't need to do my activities today because . . . ,' you know you're entering the seduction zone. You can see that you're backsliding."

What do you do? Work a little harder for a little longer, he says. "Ten more sit-ups, another lap, or three more bench presses will reinforce in your mind your ability to win fight-thrus," he says. "Just as physical training makes your body strong, perseverance and willingness to fight through obstacles will make you mentally strong." 

Stick with these steps, he adds. Before you know it, you'll have created a new, winning habit.