You’d be in good company if after a hectic holiday season, thinking about ways to be healthier seems like a punishing task. But doing so in the New Year can have especially positive results.

In a Pew Research study conducted last January, 87% of those surveyed who had made resolutions reported having kept at least one of them. And of those who made at least one, 79% of them were focused on diet, exercise, or health.

Of course, with goals ranging from consuming less sugar and reducing stress, to limiting alcohol and connecting more with friends and relatives, it can be hard to figure out where to begin. Experts say four habits are key building blocks for a healthier, longer life.

1. Workouts are nonnegotiable

Let’s get the obvious out of the way. If you haven’t already, you’re going to need to make exercise a priority. The benefits are numerous: improved mood, weight control, increased energy, and better sleep. Regular exercise can also help prevent and manage a host of health conditions including type 2 diabetes, high blood pressure, arthritis, and certain cancers.

The good news is that you can incorporate regular movement into your day to get the recommended 150 minutes of moderate-intensity activity, or 75 minutes of vigorous-intensity activity, which should be a mix of aerobic and muscle-strengthening activities.

“Don’t go from zero to 60 in a minute. Ramp up your activity slowly. Rome wasn’t built in a day. Make a goal to stay active for three months, not one year,” says Dr. Sameer Amin, chief medical officer of L.A. Care Health Plan. “Goals tend to work better in short sprints. By the time you hit the three-month mark, you will see changes in how you feel that will propel you forward.”

2. Keep your muscles limber

A good complement to a regular exercise plan is proper stretching, another habit that will help you age well.

With regular stretching, you’re keeping your muscles flexible, which allows them to maintain a range of motion in the joints. Fail to stretch and your muscles can shorten and become tight. Then, when you need those muscles for an activity, they may not be able to extend in the way they need to. The result? Greater risk of joint pain, and muscle strains.

“Stretching before and after a workout will help you release tight muscles that might be holding you back from mobilizing,” says Hannah Corbin, a Peloton instructor who teaches foam rolling, stretching, and mobility classes. “If a muscle is tight or nagging you, it’s the body’s way of telling you that it needs a little love in that area. If we ignore the tight muscles, just like anyone being ignored, they get sad and angry, and can eventually lead to injury.”

3. Befriend SPF

The stats are startling: One in five Americans will develop skin cancer by the time they reach 70. More than two people die of skin cancer every hour in the U.S. And suffering five or more sunburns doubles your risk for melanoma, according to the Skin Cancer Foundation.

This makes regular use of sunscreen a must, says San Francisco dermatologist Dr. Caren Campbell, M.D., FAAD. Go for a broad-spectrum product with an SPF of 30 or higher and reapply every two hours, or more frequently if you sweat or swim, she says. You should use about a shot glass worth to cover your entire body.

But sunscreen is not just a summertime habit. Skin-damaging UV rays are present all year long, and clouds only block about 50% of them.

“Apply sunscreen to all areas of the skin not covered by clothing,” she says. “For your face, a quarter size or two finger lengths worth of sunscreen is recommended.”

Tempted to lather on that tube you bought many years ago? Probably not a good idea.

“Don’t use expired sunscreen,” she says. ‘Sunscreen is required to be effective for at least three years from manufacturing, after which it may not be as effective. Always check the expiration date, or if it’s unavailable write the date of purchase on the bottle and toss after approximately two years to be safe.”

4. Look after your bones

About 10 million people age 50 years and older in the U.S. have osteoporosis, a disease that weakens bones, causing them to more easily break. While the majority are women, about 2 million are men. On top of that, 43 million more people, 16 million of them men, have low bone mass, putting them at increased risk of osteoporosis, a so-called silent disease because there are usually no symptoms until a bone breaks.

While “osteoporosis is the forgotten stepchild of health issues,” says Dr. Alan Beyer, board-certified orthopedic surgeon, executive medical cirector of Hoag Orthopedic Institute, and host of the Doctor in the Dugout radio show, it can be deadly. And wrist, hip, and spine fractures—which are the most common—can limit one’s independence.

“If you are over 50, both men and women should be screened for bone density once a year or every other year with a bone scan,” he says. “Once your bone health and risk for osteoporosis are assessed by your family doctor, together you can make better health decisions about treatment.”

Osteoporosis has a genetic component, Beyer says, so younger folks should find out whether the disease runs in their family. Lifestyle has an effect as well. A diet rich in calcium can help keep bones strong.

“I would encourage people, even people who exercise regularly, to add strength or weight-bearing exercises to their regimen,” he says. “Weight-bearing exercises, such as strength training using elastic bands and other easy-on-the-joints exercises, are vitally important. These exercises build bone strength, and many mature adults simply avoid strength training. Swimming is not strength training. Moreover, smoking is directly related to bone strength.”

More on aging well:

6 foods that could be making you age faster
The 5 best supplements for healthy aging, according to a longevity expert
A good workout routine can help you age better than your parents did. Here’s how
5 expert-backed ways to improve brain health at every age

New Year, new habits: 4 simple changes to help you age well