New Year’s resolutions are a tricky subject. Some love them, others mock them mercilessly. Most have heard that they’re famously unsuccessful—it’s hard to find good data, but by some estimates, around 90% of all resolutions fall by the wayside. There’s power in the idea of a fresh start, though, and if you’ve set New Year’s resolutions, that’s great—here’s how to increase your chances of success.

Be specific about what and when

“I’m going to try to exercise more” is, well, a pretty bad New Year’s resolution.

Specificity is critically important in behavior change. Take a moment to decide exactly what you’re going to do, when you’re going to do it, and even what you’re going to do if/when you fall off the wagon. This kind of algorithmic planning (which we’ve discussed before), is called setting implementation intentions, and it’s very effective.

A crucial step that’s easy to miss is deciding what to do if you fall off the wagon. It’s easy, this time of year, to plan on flawless execution, but things rarely shake out that way. Plan for setbacks and decide now how you’ll handle them. Here, then, is an improved version of the resolution above:

“Using the Couch to 5K program, I’m going to walk/run during my lunch break on Monday, Wednesday, and Friday at the gym near work. If I miss a day, I’ll simply resume the program the next Monday, Wednesday, or Friday.”

Setting specific resolutions is a bit more work than setting general, hazy ones, but it increases your chances of success.

Don't rely on willpower

Willpower cannot be trusted—it will eventually fail—so don’t trust it. Instead, set up systems in your life that keep you moving toward your goals. For me, the classic example is the grocery store.

Let’s say I’ve resolved to eat less junk food. One way to achieve this is to use willpower to resist the Chips Ahoy in my pantry (or decide to “just have one”). This will probably work for a while, but it’s bound to fail eventually.

A more effective solution is changing the way I grocery shop by installing the following rule: “no buying anything that’s not on the grocery list.” Keeping Chips Ahoy off the grocery list is easy—keeping them out of my mouth when they’re beckoning me from the pantry is not so easy.

So whatever changes you’re hoping to make in 2019, I urge you to be specific and banish willpower.