Depicted on Roman coins as two-faced, Janus, for which the month January is named, looks both to past and the future.

It's fitting that Janus wears his duplicitous guise, as January can be a fickle friend. Filled with promise - many we make to ourselves as New Year's resolutions - cold, damp, dim January seems a bleak, dismal, and self-defeating option for renewed optimism.

Is it any wonder, then, why so many of our highest hopes for ourselves are packed away again like holiday decorations by mid-January?

It's said that it takes 21 days to inscribe a new habit. If you find it hard to make it more than that magic three weeks, however, you're not alone.

Emma Reynolds wrote in the British newspaper the Daily Mail that 75 percent of adults said they were no longer confident in their resolutions all through January, many of which involved a new fitness routine.

Fitness experts cite a number of factors conspiring to prevent our success.

"I think a big part of it is setting unrealistic goals," Wellness Center at Meadowmont lifestyle enhancement director Kathy DiBlasio said. " 'Oh, I haven't lost a pound, and I've been doing this for two-and-a-half weeks now.' Well, you may not lose a pound: you're adjusting...or your body doesn't know what to do."

Another hurdle can be assigning oneself exercises that aren't enjoyable.

"Not only can exercise be fun, it can help fill gaps in your life," Melissa Sperl wrote for WeightWatchers.com.

"If you sit in front of a computer, exercise can be a social thing for you," Sperl said. "If you never see your spouse, exercise together."

Chapel Hill/Carrboro YMCA health enhancement director Kevin Cragwell agreed.

"It has to be something that the person will like to do," Cragwell said. "On the YMCA's (cardio) machines, people now have television screens right there at the user's disposal," Cragwell added. "They can watch different programs, there's an iPod carriage ... or they can play games like solitaire and backgammon, all so that there's not this sensory deprivation while (exercising)."

Another path to an "easy way out" of our resolutions includes a lack of investment - both financial and emotional. Health clubs and spas feed of the notion that those making a financial commitment to health and fitness are less likely to rationalize their way out of their new fitness regimen, especially in trying economic times. Similarly, those imagining a new self image alone disappoint only themselves by coming up short. No appointments are broken, no wagers are lost.

So what are we to do when we find the last vestiges of our best hopes hanging by a thread?

The first step is to reassess and give our goals a reality check.

George Krueger and Mary-Lynn Foster wrote for the website BiggSuccess.com that we need to remind ourselves of why we made the resolution in the first place.

"You had a good reason, right?" they wrote. "If not, go ahead and give up on it; if so, remind yourself of the reason behind it."

Krueger and Foster added that visualization of end goals can promote adherence to resolutions as well: "Picture yourself having already achieved it. ... Use this motivation to inspire you to press on."

After reassessing, scrutinize the achievability of goals. Those trying to lose five pounds a week by bathing suit season may find their routines shelved halfway through January.

"If you are trying to lose weight, the recommended weight loss per week is one to two pounds, so a goal could be lose eight pounds in a month," eHow.com writer Kris Larsen said.

If a goal is achievable and fun, it can be habit forming.

"Commit to trying it consistently for at least three weeks," Sperl suggested. "If you still think you hate it after that amount of time, give yourself permission to say, OK, this isn't working. Then pick something different and repeat."

Another motivating factor is peer pressure.

"A workout partner can be immeasurably helpful," Sperl said, "because you have a responsibility to your friend not to talk yourself out of exercising. Try to choose a buddy who's in about the same shape as you."

"Tell someone about your goal: accountability," DiBlasio added. "You're more apt to stick with a goal if people are always asking you about it. You can even start a challenge or a bet with someone you're going to work out with."

"If they have a roommate or a friend that wants to do the same thing, then definitely do it together," UNC associate director of recreation and fitness director Lauren Mangili said.

In late January, fitness centers will often offer a full menu of challenges specifically designed to keep members motivated.

"The YMCA will soon start up our Fitness Challenge, which will officially start in mid-to-late February, and the major goal of this is to just keep people going," Cragwell said. "It's primarily self-directed with a list of activities that we're asking folks to keep up with."

DiBlasio said these work particularly well if there's a small investment involved.

"Be financially-engaged, because then you've got a financial investment as well as an emotional investment," she said.

Cragwell added that simplicity is a good idea for those beginning a routine.

"An orientation that I like to provide is to identify the handful of pieces that will yield a full-body workout - including cardio - which will get them back on the right path," he said. "I can put together a routine that will have them in and out of the gym in under 45 minutes."

"Many people believe that exercise requires a large daily time commitment or that it has to be physically difficult and demanding," Sperl said. "But the truth is that even small amounts of light activity can make a big difference in your weight loss."

As such, experts say to start slowly.

"An hour-long high-intensity aerobics class on your first day will only discourage you...and may send you back to square one," Sperl cautioned.

"It takes 21 days to make a habit," Larsen said. "As the 21 days progresses, then increase your level of difficulty. You can also add in another activity."

One of the most important factors in the long-term success of a new fitness routine is short-term forgiveness. Missed a workout? Get over it; get back to it.

"The sooner you get back, the easier it's going to be, and it's not going to hurt as bad the less time that elapses." DiBlasio explained.

"Putting something on the calendar doesn't mean there won't be other priorities that come up," Mangili said. "Life happens, and you should plan to be flexible."

"When you stop ... your energy level starts to drop, so it's even harder to jump back in," Sperl said.

"(Let's say) yesterday you fell off the wagon," Krueger and Foster wrote. "You're only human. Maybe you were tempted, but how can you remove the temptation in the future?"

Lastly, perhaps our double-dealing deity Janus doesn't smile upon you.

"On average, we will have failed in sticking to the same resolution a disappointing four (years)," Reynolds wrote.

If all else fails, perhaps a promise of the new month, week, or day is a better fit than Jan. 1. Your new year might just start today.