The 30-day challenge is here. But is that long enough to form healthy habits? Experts weigh in.

Resolutions are top of mind at the beginning of a new year — coinciding, of course, with the marketing of 30-day programs that promise to help individuals achieve their long-term goals.

But experts warn that before starting any sort of challenge, people should consider what changes they want to make and how to best turn those into habits that will stick.

"What you're aiming for is something to become effortless and automatic," writer Gretchen Rubin tells Yahoo Life of forming habits. "I think almost all of us have something that we would like to change, and so if someone can promise it to be fairly painless it's tempting. But the funny thing is, it's actually not that hard to change a habit when you do it in a way that's right for you."

Rubin, author of The Happiness Project, Better Than Before and The Four Tendencies has built a career on studying and writing about human nature and the ways that it impacts an individual's tendencies. Her main takeaway from her work is that there's no "one-size-fits-all" approach to implementing new behaviors — or getting rid of old ones. Unfortunately, that means that the various 30-day programs that kick off on January 1 aren't always the pathways to success that people want them to be.

"Everybody wants there to be one best way, one magical answer, to do something for 30 days and that's gonna yield the desired result. But it just doesn't work that way. People are wildly different," Rubin says of these standardized programs. "We want to outsource it. We want to throw money at the problem, hire a wizard, but a lot of times they just have their own thing they're selling."

Rubin's mindset applies specifically to the 30-day fitness challenges or diet fads that are widely marketed as the new year approaches. Cortland Dahl, Chief Contemplative Officer at Healthy Minds Innovations and creator of Healthy Minds Program App, tells Yahoo Life that the promotion of these programs are likely informed by the science of human behavior.

"The economy really is built on very sophisticated neuroscience — and really a lot of very smart people trying to manipulate our attention and emotions," he says.

Still, they're likely to encourage moments of inspiration to start a new task or implement a new lifestyle change, rather than providing the tools to actually do so.

"A new habit begins with inspiration. You read an article, you talk to a friend, you hear something in your favorite podcast and you think, 'Oh yeah, I should do that.' You're kind of excited, you're fired up. And then it just sort of seems like it should be easy," Dahl explains. "But inspiration is fragile and fades pretty quickly. Then you're just left with nothing else to support it. And that's where people then drop the habit."

While Dahl explains that habit forming essentially comes down to repetition — repeating an action until it goes from a fleeting brain state to an enduring brain trait — Rubin warns that a 30-day program can work in opposition to that process simply by having an end date.

"A 30-day challenge is a great way to meet a goal. If you say, 'I want to exercise, I want to do yoga for 30 days.' Well, a lot of people are really good at doing that. But the problem is they think if I do it for 30 days, then I will have started the habit. And it just doesn't work like that," she explains. "You always have to be thinking about well, what about the 35th Day? What about the 60th Day? What about the 5,000th day? Because 30 days gives you a finish line. And then once you finish, you have to start over. And starting over is hard."

Instead, people need to think more deeply about the existing structure of their days and even reflect on habit forming behaviors that have worked in the past to determine how to be successful in the future.

"Really the challenge is to do the thinking about it so you set yourself up for success. It's actually easier than some people assume because they've been doing it the wrong way," she says. "You have to start with self knowledge, and just acknowledging the truth about how you fail or succeed."

Rubin's development of the four tendencies allows people to do just that by defining the different ways that individuals might respond to expectations and how they can better approach decisions and deadlines. This individualized approach also takes the pressure off of the idea of "failure," she explains.

"You can succeed by failing," she says. "If something doesn't work for you, that is just information. So I think people should not feel bad when something doesn't work, because it's like, well, now you know something about yourself."

Dahl also reminds readers that while there are ways to properly support new habits, the world is already full of distractions that can make habit formation difficult.

"We beat ourselves up because we want to eat healthy, we want to sleep better, we want to exercise, we want to meditate, whatever it is, and then we find it difficult. And the reality is the world around us is oftentimes thwarting that," Dahl says. "One practical thing we can do is almost focus more on the support at the beginning. Make some space for some podcasts or conversations that are supporting the habits you want to build, or what you read, or what you watch. It doesn't have to be everything, but even a few can just take you into that space where the inspiration will be strengthened and not undermined."

But just as there's no magic process to forming habits, Rubin says there's no magic number of days that ensures habits, either.

"There's some research that says 66 days, but that's meaningless," she says, "because some things never became habits for some people. And some things became habits in shorter and some longer periods of time. So it all depends."

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