Trying to Lose Weight? Here's Why Strength Training Is as Important as Cardio

When exercising to lose weight, many people hit the treadmill or elliptical and spend their entire workout grinding away on it. For whatever reason, they neglect to hit the weights—whether they're unsure of how to use them or have preconceived—and often inaccurate—beliefs about what strength training will do to their bodies.

If this sounds like you, you might be missing out on an important ingredient in your recipe for optimal health and weight loss. Building muscle has numerous benefits. And you don't have to lift heavy or have a lot of fancy equipment to make it happen.

Here's how strength training benefits weight loss and health, plus a few tips and moves to get you started.

Maintain Muscle Mass to Burn More Calories

When you lose weight, you're not just losing fat. You're also losing lean tissue, which includes muscle and bone mass—per a 2021 review in Nutrients. Your organs might even decrease in size.

But the scale doesn't reflect this—it does not tell you where the weight loss is coming from. So if you're consuming fewer calories without strength training, you might be losing a disproportionate amount of muscle and other lean tissue compared to fat. Consequently, your body composition, which is a measurement of fat tissue compared to lean tissue (muscle, bones, organs), may end up at an unhealthy ratio, despite the scale saying you're at a healthy weight.

On the flip side, maintaining or adding muscle to your frame can make the needle on the scale slow down—even though adding muscle mass improves your body composition. This is why many health professionals recommend stepping away from the scale and focusing on other factors to gauge your progress.

"Muscles are fat-burning machines," says Wendy Batts, M.S., assistant professor of exercise science at PennWest California and a regional master instructor for the National Academy of Sports Medicine. "So the more muscle you have, the more calories you're going to burn."

And "the burn" doesn't necessarily end after your workout ends. Depending on the intensity and type of exercise you're doing, your body may burn calories at a higher level for up to 24 hours after your workout ends. This is known as the afterburn effect—or technically, excess post-exercise oxygen consumption (EPOC).

According to a 2021 study in the International Journal of Exercise Science, previous studies showed that greater EPOC takes place with higher intensity or longer duration exercise. The researchers in this study compared circuit-style resistance training (RT) and high-intensity interval training (HIIT).

The RT group performed a full-body strength training circuit, doing 30 seconds of each strength training exercise and resting for 1 minute between sets; the entire circuit was repeated 4 times (resulting in 4 sets per muscle group). The HIIT group ran at ≥ 90% VO2 max for twenty 30-second intervals with 1-minute rest in between each interval (90% VO2 max is very intense and almost maximal effort).

The study results showed that both groups had elevated metabolisms for at least 14 hours, but less than 24 hours. In other words, both types of exercise increased EPOC.

On another note, having more muscle mass means more calories are used in general—it's one reason men tend to lose weight more quickly than women.

And while the amount of muscle mass an average woman typically adds to her frame from strength training a couple of times a week may not make a huge difference in her metabolism, taking advantage of EPOC, eating healthy and adding muscle all add up. "Obviously, burning more calories throughout your day, combined with a sensible diet, is going to maximize your weight loss," says Batts.

Other Benefits of Strength Training

Calorie burn and fat loss are not the only benefits of strength training. "Weight training improves your posture, helps your endurance, builds strength and reduces your chance of injuries," says Batts.

Strength training may also help prevent and manage disease.

An interesting 2018 study in Cardiovascular Diabetology suggests that adding muscle through strength training may reduce the risk of metabolic syndrome, characterized by a cluster of several factors, including large waist circumference (signifying too much belly fat), high cholesterol, high blood pressure and high blood sugar levels.

While we tend to think of cardio exercise as being the preference for lowering blood pressure, research shows that strength training can also play a starring role.

Strength training can also help manage diabetes by lowering blood sugar levels and improving insulin response.

And 2020 research in NeuroImage: Clinical suggests strength training may even protect the brain and prevent cognitive decline.

Getting Started

One myth many women fall for when considering strength training is believing it'll make them bulky, like a bodybuilder. "If you're training to be a bodybuilder, you're going to be eating more. You're going to be training with heavy weights, doing fewer reps and isolating different muscles," explains Batts. "To lose weight, you're going to monitor your calorie intake and do more reps with lighter weights."

And one mistake many make when starting to strength train is going too heavy too soon.

"Where people get into trouble is when they start by lifting heavy," says Batts. "They go to the gym, pick up 10 pounds, and then try to lunge or squat or curl. And the next day they're so sore and miserable that they get discouraged and quit."

Instead, Batts suggests starting with your own body weight. Your goal is to do 12-15 repetitions while keeping proper form and technique. As you get stronger, gradually add more weight.

If you don't want to join a gym and have no dumbbells at home, household items will do, says Batts. Start with soup cans and slowly work up to lifting milk or laundry detergent jugs (partially filled). Try carrying a full laundry basket while you do a set of walking lunges.

"You don't have to have a really heavy weight in the beginning, especially if it's for weight loss," says Batts.

And remember to change things up.

"Do something new every week—even if it's just a little change—so you're challenging your body in a different way," advises Batts. "You'll be using different muscles and expending more calories."

Small changes in positioning, for example, will recruit different muscle fibers, increasing the difficulty and triggering muscle growth and strength increases.

And take the time to stretch following a strength training workout. While more research needs to be performed, there is some evidence that suggests that regularly stretching after strengthening the muscles may increase muscle growth and strength, per a 2020 study in the Journal of Science in Sport and Exercise.

It's important to note that it is unnecessary—and not advised—to train the same muscles every day. Muscles need rest to grow. Leave at least a day in between strength training the same muscle groups. If you do a full-body workout each time you strength train, leave at least 24 hours between each session. If you want to do some strength training every day, split it up. For example, you could do upper body and core one day, lower body the next, and keep alternating.

If you're unsure of what to do and really want to add strength training, hire a certified personal trainer to design a program for you or use one of the many available apps for strength training programs. You can also find free workout videos on YouTube.

The Bottom Line

There are many reasons to add strength training to your exercise regime. Combined with a healthy, varied diet, engaging in strength training can improve your body fat percentage—even if it doesn't show up on the scale. It also improves posture, prevents disease and helps you move more easily and efficiently. The key, as with any other habit change, is to do it consistently and give your body time to see the changes.