If you’re aiming to lose fat while building muscle, you’re not alone—it’s a common goal and a key to transforming your body composition and appearance. But let’s be real: it’s not as simple as it sounds. Dialing in your diet and committing to consistent exercise are crucial, and strength training is one of the most effective tools to help you get there.

Why strength training? It doesn’t just torch calories during your workout; it keeps your metabolism revved long after. Building muscle also shifts your body composition and improves how efficiently your body burns fat overall. To break it all down, I spoke with fitness experts who explained exactly how strength training supports fat loss and what strategies will help you maximize results.

Looking for more fitness tips? Check out how many calories you need to burn to lose weight, simple ways to shed body fat at home, and how to achieve that elusive balance of losing weight while gaining lean muscle.

Cardio versus strength training

There's a constant back-and-forth argument about which is more efficient in reaching your ideal physique: cardio or strength training. According to New York City-based personal trainer Oscar Colon IV, cardio is ideal for burning more calories during a workout session — and it's key to keeping your heart strong — but strength training affects your body differently. "Strength training has a two-pronged effect because you burn calories during the workout and during the recovery and restoration of muscle groups you worked," he says. As a result, you get more results for your effort.

It's still a good idea to incorporate both cardio and strength training into a well-balanced fitness plan, so you can reap all the benefits. How much you do of one or the other may also depend on your current goals. If you're training for your first marathon, cardio will be your main focus as you build endurance, whereas strength training will be a priority when you're trying to get stronger or build muscle.

Read more: Changing Your Body

How muscles affect your ability to burn fat

As mentioned, strength training can help you burn more calories during and after your workout. This is thanks to the lean muscle you gain as a result of strength training. If your goal is to lose weight, having more lean muscle can help the process.

This also means that the more lean muscle you have, the higher your resting metabolic rate will be. Your resting metabolic rate, or RMR, refers to the total number of calories your body burns when it's at rest. Biologically speaking, resting metabolism aids your organ functions, neurological functions, breathing and blood circulation. Rachel MacPherson, an American Council of Exercise-certified personal trainer, performance specialist and Garage Gym Reviews expert, explains that muscle is metabolically active, meaning it burns calories even at rest, and although the effect is small, it's significant and does add up over time. "This also helps to counteract the decline of metabolism and muscle mass as you age, which can contribute to middle-age weight gain," she says.

Strength training also has fat-burning benefits when you're fresh off a workout. "Excess post-exercise oxygen consumption is the process of your body regulating itself back to homeostasis after a strenuous workout," Colon explains. In other words, you're still burning calories as you recover, since your body stays warm for a while as it cools down.

How long it takes to put on muscle

Now that you know that lean muscle is the key component in fat burning, you're probably wondering how long it takes to build muscle. This will vary from person to person, since genetics, hormones, gender, diet and other factors play a role in how much muscle you put on and how quickly. "If you consistently train three to four times a week for 30 minutes each session, you should realistically start to see results in three to four weeks," Colon says.

MacPherson says you can put on muscle mass each week, and doing a 12- to 16-week hypertrophy training program is ideal for seeing a significant amount of muscle gain. "You can expect upwards of five to 10 pounds of muscle gain during this time," she explains, adding, "As you become more advanced you will need to work harder for less gain, but you will still see results."

That's another interesting aspect of strength training: If you're a beginner, you tend to have an advantage over someone more experienced when building muscle. This is what some people refer to as "newbie gains," which refers to your body's muscle-building response to lifting weights since it's not used to this kind of stimulus. Research has shown that untrained individuals (those with minimal to no strength training experience) can put on muscle faster than someone who's already experienced with strength training. 

Generally speaking, men and women also have different results when building muscle mass. "Men can build muscle mass much easier and faster than women due to testosterone, while women can still build substantial amounts of muscle, but will never look as large or full as men unless they use anabolic steroids," elaborates MacPherson. She adds, "It's vital that women lift enough volume and weight while also eating enough to support muscle gain." This means letting go of the old-school mentality of dieting and shrinking yourself, otherwise it'll inhibit your ability to build muscle.

Besides a well-regimented workout plan, a diet that supports muscle-building is key too. MacPherson says, "In order to build muscle, you need to eat in a calorie surplus with plenty of protein." She explains that eating in a surplus will lead you to gain some body fat, which is normal and necessary to gain muscle. "You can lose it afterward and it will be easier since your body has become better at burning calories due to increased muscle mass," she adds.

Other benefits to lifting weights

Besides helping you metabolize and get stronger, strength training has other benefits. Colon says it's also important for bone development and density. "Weight-bearing exercises put temporary stress on your bones, sending a message to bone-building cells to take action and rebuild bones stronger," he explains.

Another benefit tied to strength training is reducing your risk of injury by improving the strength, range of motion and mobility of your muscles, ligaments and tendons. "This can reinforce strength around major joints like your knees, hips, and ankles to provide additional protection against injury," Colon adds.

Another plus is for your heart, since strength training is shown to help decrease blood pressure. You can also reduce the chances of type 2 diabetes, improve blood circulation and lower LDL (bad) cholesterol. Exercise has been shown to even have a positive effect on your mental health, and resistance training has been found to ease anxiety as well.

Bottom line

It's helpful to know the unique effects strength training has on your body as you establish a consistent exercise routine. Not only will you naturally burn more fat by having more muscle, but you'll maintain strength as you age and improve other functions of your life as well. If you don't have access to a gym, you can start your exercise regimen at home and still get the same results, as long as you have the proper equipment.

Even if your goal isn't weight loss or body recomposition, strength training provides many benefits that make it worth adding to your lifestyle, and it'll only improve your well-being in the long run.