1. Strength Training Supports Fat Loss
Ever hear of the after-burn effect? It's technically called excess post-exercise oxygen consumption, or EPOC, and it means that you need more oxygen after training as your body works to cool itself down. In the process, you're burning more calories than usual, even once you've plopped yourself down on the couch.
This mini metabolism boost is stronger with more intense exercise, like high-intensity interval training (HIIT) and heavy strength-training sessions with little rest, because you'll need loads of oxygen to fuel harder workouts, according to the American Council on Exercise.
But when you're hitting that high-intensity level, the metabolism lift isn't so mini after all: The after-burn can linger for up to 21 hours post-strength training, according to a small June 2015 study in Research Quarterly for Exercise and Sport. Over time, this increased energy expenditure adds up, supporting your ability to shed body fat.
You'll also burn more calories at rest if you have more lean mass, aka muscle, than fat — and strength training is the best way to make that happen. "Resistance training has been shown to be more effective for building lean body mass over time than cardio," Li says.
2. It Can Transform Your Body
If you're only using cardio to change your body composition — the amount of muscle vs. fat on your frame — you'll typically plateau quickly. Consistent strength training, on the other hand, can seriously transform your physique.
Sure, cardio can help you lose weight, but if your goal is to see strong, defined shoulders, abs and legs in the mirror, strength training is the way to get there.
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3. Strength Training Builds Confidence
The physical changes that come with strength training are motivating and exciting in themselves, but building strength has an undeniable influence on your confidence that might be even more valuable. "Most people don't start out able to do great push-ups or pull-ups, for example, but training to achieve these things and unlocking those new skills is highly motivating," Matheny says.
Don't be surprised if the sense of pride that comes with reaching new strength goals carries over into your life outside of the gym.
4. It Can Help Your Mental Health
Though aerobic (aka cardio) exercise like walking and cycling has been extensively researched — and applauded — for its mental health benefits, strength training has begun to claim its share of the spotlight.
In fact, a July 2013 review published in Neuropsychobiology found that strength training, particularly high-intensity strength training, can help lessen symptoms in people with depression.
"A combination of moderate-intensity aerobic training and high-intensity strength training may provide more positive benefits than other exercise programs," the study authors wrote.
5. Strength Training Improves Balance
Maybe you want to finally nail that one-legged yoga pose or get up and down the stairs without feeling wobbly. No matter your goal, strength training can support your stability.
"Many strength-training movements require balance and mobility from your body," Matheny says. As you move in different planes of motion and at different angles while strength training, your major muscle groups and the smaller muscles throughout your body become stronger and more stable.
Falls are the leading cause of injury-related death in adults over 65, per the Centers for Disease Control and Prevention, so feeling balanced and stable in your body becomes increasingly important as you age.
6. It Makes Everyday Tasks Easier
That improved balance will come in handy when you need to stand on your tippy-toes to reach something in the closet. And so will the overall strength you build, for all sorts of daily activities.
"If you have trained to deadlift a heavy kettlebell, for example, you feel much more confident — and are safer — picking up boxes for, say, moving," Matheny says. The stronger you are in your strength-training workouts, the stronger you are out in the world.
7. Strength Training Helps Your Posture
Being stuck in one position all day — like sitting at your computer — fatigues the stabilizer muscles in your torso, which play a major role in your posture, Li says.
Regular strength training will help you move more throughout the week, but it also helps increase the endurance of the muscles in your trunk that are responsible for proud posture, he explains.
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8. It Can Boost Your Sports Performance
Strength training might also help you get better at your favorite non-gym activities. "Sports that require a lot of short bursts of power and longer periods of low activity or rest benefit tremendously from strength training," Li says.
Whether you want to knock a baseball out of the park, perfect your golf swing or even just run faster, developing strength and power with resistance training can level up your performance.
A large body of research backs this up, including a March 2012 review in the International Journal of Sports Physiology and Performance, as well as smaller sport-specific reports. For example, a June 2016 study in the Journal of Strength and Conditioning Research found that six weeks of strength training improved professional soccer players' sprinting ability, while a May 2014 study in Scandinavian Journal of Medicine and Science in Sports found 25 weeks of heavy lifting helped cyclists pedal more powerfully.
9. Strength Training Supports Healthy Bones
Though you may think of your bones as static, they break down and renew themselves, much like your muscles.
Over the years, though, bone breakdown increases — especially in women, who have smaller bones to begin with, says Vivian Ledesma, DC, owner of Alliance Healing Arts in Seattle. (Many women develop osteoporosis, the condition of porous, weak bones in middle-age and beyond, according to the International Osteoporosis Foundation)
Though nutrition, age and hormones all influence bone health, people who regularly strength train tend to have higher bone density, Li says. Just as strength training stimulates the repair and growth of your muscles, so it does for your bones.
Ultimately, strength training is important both for supporting bone growth during our younger years and maintaining as much of that bone as possible as we age. A small August 2013 study in the Journal of Sports Science and Physical Fitness, for example, found that full-body resistance training was an effective way for premenopausal women to maintain bone mineral density.
10. It Can Help Keep Your Blood Sugar Healthy
Strength training can help reduce your risk of diabetes, a metabolic disease characterized by high blood sugar that affects 422 million people worldwide, according to the World Health Organization.
In fact, April 2019 research in Mayo Clinic Proceedings found that people with moderate levels of muscular strength had a 32 percent lower risk of developing type 2 diabetes than those with low levels of muscular strength.
Researchers think resistance training has this effect by helping to improve body composition and sensitivity to the sugar-regulating hormone insulin, according to an American Diabetes Association position statement published in November 2016 in Diabetes Care.
11. Strength Training Supports Your Heart
Though cardio has long gotten credit for its heart health benefits, January 2017 research in Medicine and Science in Sports and Exercise suggests resistance training deserves some, too.
The study authors found that women who reported engaging in any strength training had a 17 percent lower risk of developing cardiovascular disease than those who did no strength training.
12. It May Help You Live a Longer, Healthier Life
Remember those guidelines for physical activity at the top of this story? Well, following those — doing two full-body strength-training workouts and 150 to 300 minutes of moderate-intensity cardio each week — has been associated with "greatly reduced risk of all cause and cause specific mortality," according to a July 2020 study published in The BMJ.
And given all the other benefits listed here — improved heart and bone health, healthy blood sugar levels and better mental health — it makes sense that resistance training would result in a longer, healthier life.