Want to lose that belly fat and get back into your skinny jeans? New research from Harvard says the secret is resistance training. Here’s more about the latest findings—along with tips for getting the most out of a resistance training workout.

I lift weights four times a week. The rest of the time I may do yoga, ballet barre, walk, hike or sprint. But to get the results I'm shooting for, my weight training days are non-negotiable. Here's why:

Is your waistline expanding a little bit (or a lot) each year? And is it getting harder and harder to fight that belly fat even if you diet and exercise every day?

If so, you’re not alone. In my medical practice, “waistline creep” is one of the most common complaints I hear.  And it’s a serious problem, because belly fat isn’t just unsightly; it also increases your risk of diabetes, heart disease and even breast cancer.

But new research points to a simple solution—and it doesn’t involve cutting calories or doing hundreds of sit-ups. Instead, it involves resistance training.

What the research shows

In a large-scale study, researchers at Harvard followed more than 10,000 healthy men, aged 40 or older, for 12 years. The men provided information on the types of exercise they did and the amount of time they spent exercising.

It turns out that men who did 20 minutes of weight training every day had a smaller increase in belly fat than men who spent the same amount of time doing moderate to vigorous aerobic activities. (And not surprisingly, the men who were sedentary had the biggest increases in belly fat.) Combining weight training and aerobic exercise led to the best results.

Why weightlifting works

Why does resistance training target your “muffin top” so effectively? Here are the two primary reasons:

• Muscle burns far more calories than fat. So when you add lean muscle to your body with resistance training, you burn more energy all day long—not just when you’re exercising. And that means burning off belly fat, which is easy for the body to mobilize when it needs fuel.
• Resistance training builds strong core muscles in your abdomen and back, and a toned core takes inches off your waistline.

Moreover, weight lifting doesn’t just strengthen your core; it makes you stronger all over. When you get stronger, you have more energy, and that means you do more and you sit less. So again, you’re burning more calories—and that whittles off more abdominal fat.

The right way to do resistance training

Obviously, it’s smart to add resistance training to your regimen if you want to win the battle of the bulge. While the men in the Harvard study exercised every day, I recommend doing just three or four sessions a week. That way, your body can rest and recover in between.

Here’s how to get the maximum payoff from your weightlifting:

• Pick a heavy enough weight. Here’s a good rule of thumb: If you can easily lift the weight for more than five repetitions, it’s too light.
• Do “low reps.” That means repeating each exercise five times or less.
• Do multiple sets. Start with two sets if you’re a beginner, and gradually work up to twelve.

And remember that resistance training doesn’t just mean lifting weights; it also means using your own body weight. Try these three powerful core exercises, which will rev up your metabolism and really burn off belly fat:

• Planks. To do a plank, hold your body in a “pushup” position, with only your toes and your hands on the floor.
• Squats.  Start with the “goblet” squat, which is easy to do correctly. Hold a dumbbell or kettlebell in front of your chest like a goblet. Stand with your feet slightly wider than hip-width, and point your toes slightly outward. Continuing to hold the weight in front of your chest, sit down as if you’re trying to plant your fanny on the ground. Go as low as you can while keeping good form (heels on the ground, knees in line with toes, flat back). Then stand up, keeping your back vertical.
• “Mountain climbers.” Start in a plank position. Pull one knee at a time to your chest and then return to the plank position. Repeat with the other leg.

These exercises can be a little tough when you’re just starting out. The trick, however, is to do them for only 15 seconds in each repetition. That doesn’t sound like a lot, but believe me: You’ll feel it the next day, especially in your core.

Boosting your belly-fat-fighting efforts

If you take up resistance training to battle your belly fat, get more bang for your buck by combining it with a low-carb diet. Sugar and grains are the biggest dietary culprits when it comes to visceral fat, because they cause metabolic syndrome—and metabolic syndrome leads to a big belly.

Also, add in a few minutes of meditation each day. Research shows that mindful meditation can actually reduce belly fat. And get enough sleep, because sleeping less than five hours a night can add pounds to your waistline.

Put all of these elements together, and you have the perfect recipe for melting off that belly bulge. I’m betting that within weeks, you’ll see a difference… and within a few months, you’ll be zipping up jeans you never thought you’d fit into again.

Keep thinking big and living bold!

-Dr. Kellyann