How Weightlifting Burns Body Fat, Even After You Work Out
Weightlifting has a unique effect on your body's ability to burn fat. Here's what to know.
Giselle Castro-SlobodaFitness and Nutrition Writer
I'm a Fitness & Nutrition writer for CNET who enjoys reviewing the latest fitness gadgets, testing out activewear and sneakers, as well as debunking wellness myths. On my spare time I enjoy cooking new recipes, going for a scenic run, hitting the weight room, or binge-watching many TV shows at once. I am a former personal trainer and still enjoy learning and brushing up on my training knowledge from time to time. I've had my wellness and lifestyle content published in various online publications such as: Women's Health, Shape, Healthline, Popsugar and more.
Strength training is one workout that helps your body burn fat -- not just during your workout, but afterward, too. In fact, there are many ways putting on muscle affects your body composition. We spoke to some experts to help explain how this phenomenon works.
Cardio vs. strength training
There's a constant back-and-forth argument about which is more efficient: 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 in a different way. "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 explains. As a result, you get more bang for your buck.
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 is going to be your main focus as you build endurance, whereas strength training is going to be a priority when you're trying to get stronger or build muscle.
How muscles affect your ability to burn fat
As mentioned, strength training has the ability to 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 even though 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," explains Colon. 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. Colon says, "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."
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," explains MacPherson, 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 about 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," he adds.
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 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.
The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.