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The fitness world loves the debate: cardio or strength training? Which workout is best, and which can you cut from your exercise routine? The reality is cardio and strength don't need to be mutually exclusive nor should they be.

"Both (cardio and strength training) need to be included in a well-rounded exercise program," says Michael Rebold, certified strength and conditioning specialist and director of integrative exercise sciences at Hiram College in Ohio. That's true whether you are vying for improved body composition, heart health or longevity.

"They complement each other," says Dr. Daniel V. Vigil, a family medicine and sports medicine physician with UCLA Health in California. "Many of our acts of daily living rely on having efficient cardiorespiratory and musculoskeletal systems." For example, walking the dog, playing with the kids or running to catch the bus rely predominantly on aerobic fitness, while getting up off of the floor, carrying groceries and performing home repairs rely more so on muscular fitness. Perhaps surprisingly, that's also true of activity such as taking the stairs. Strength plays a bigger role than cardio in determining if you can make it up a flight of stairs without getting winded.

For most people, how much time you should devote to cardiovascular forms of exercise versus resistance training depends on what you enjoy most. "The best exercise, from a public health perspective, is the one that you actually like and will do," Vigil says. That said, the right workout for you also depends on your individual health and fitness goals.

Below, experts share the unique benefits of cardiovascular exercise and strength training and how to get the best of both workouts.

Body fat levels. Exercise of all kinds reduces body fat levels by expending energy. That includes cardiovascular exercise as well as weight training. Intensity is the most important determiner of how many calories you burn during a workout, says Dani Singer, a certified personal trainer in Baltimore. He's also CEO and founder of Fit2Go Personal Training.

Weight loss is caused by burning more calories than you consume. This fact leads some people to assume that the type of exercise that burns the most calories will also produce the most fat loss, Singer says. That's an incorrect assumption.

"In reality, strength training is the most effective type of exercise to reduce body fat percentage," Singer says.

It's important to distinguish the difference between weight loss and fat loss, he explains. "For most people, their actual weight isn't really what they care about," he says. "They don't care about how heavy they are. They care about how lean they are. When your body is in a caloric deficit, it will burn anything it can for energy. That means it will burn fat, yes, but it will also burn muscle tissue."

The way to counteract this is to engage in weight training, which tells your body that it needs the muscles being exercised, Singer says. "This leaves your body with no choice but to burn fat, leading to a leaner body as a result," he says.

Resistance or weight training has other benefits, adds Jonathan Jordan, a personal trainer based in San Francisco. "Strength training helps ensure healthy bones, joints and muscles," he says. "It builds lean muscle mass, which is incredibly important as we age."

Research suggests that weight training is important when it comes to decreasing body fat.

For example, a study published in 2017 in the journal Obesity suggests that weight training in combination with a low-calorie diet can help older adults become slimmer while preserving lean muscle mass that might be lost through aerobic workouts.

Researchers at Wake Forest University studied obese or overweight adults who were in their 60s. The study suggests that participants who lost weight and engaged in resistance training lost less lean mass than those who shed pounds through aerobic training.

Cardiovascular health. With a name like cardiovascular exercise, it stands to reason that cardiovascular exercise would benefit heart health. And it does. However, it's important to note that all exercise increases the workload on the heart and lungs and is therefore cardiovascular to some degree. While cardiovascular is the most common term, aerobic is the more scientifically accurate term for activities such as jogging and cycling.

"Of the two, aerobic or cardiovascular training is more directly important than anaerobic or strength training, since it more effectively builds aerobic fitness (the body's ability to deliver oxygen to tissues and use it)," says Vigil.

Strength training and the muscular adaptations that come with it affects heart health more indirectly. By increasing muscle mass, it gives your cardiovascular system more places to store its blood, thereby reducing blood pressure on the arterial walls, explains Scott Collier, a researcher and professor of cardiovascular exercise science at Appalachian State University in Boone, North Carolina.

By reducing levels of visceral fat, strength training also significantly lowers heart disease risk, says Andrew R. Coggan, associate professor of kinesiology and integrative physiology at Indiana University-Purdue University Indianapolis. In fact, regardless of overall body fat percentage, carrying excess visceral fat increases the risk of cardiovascular disease, according to a 2016 study published in the Journal of the American College of Cardiology. And a previous 2015 study from the journal The Lancet identified grip strength a widely recognized surrogate for total-body muscle strength as more accurately predicting the likelihood of death by heart disease than blood pressure.

Muscle health. There are two main varieties of muscle cells, or fibers: type 1 (also called slow-twitch or aerobic) and type 2 (known as fast-twitch or anaerobic), says Coggan.

Low-intensity or sustained cardiovascular exercise (movements longer than a few minutes) primarily use the type 1 fibers, Coggan says. The fibers that are trained are the ones that adapt. They do so largely through increasing the size and number of mitochondria, the microscopic oxygen-using power plants within your muscle cells, as well as capillaries, small blood vessels that bring nutrients including oxygen to the body's tissues, while removing carbon dioxide and other waste products, he says. These adaptations increase muscle endurance.

These are good cardio exercises for type 1 muscle fibers:

However, high-intensity, sprint-like cardiovascular exercise as well as strength training, especially at a high intensity, predominantly works type 2 muscle fibers, though such exercises also work type 1 fibers to a lesser extent. During a process called hypertrophy, muscle fibers adapt: The contractile units of each muscle cell grow and, eventually, the muscles as a whole are larger. As the contractile units grow, the muscle is better able to contract, resulting in greater strength and power, Rebold says.

Video: Calorie counters on treadmills and ellipticals aren't as accurate as you may think (Business Insider)

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If you're about to start weight training, it's best not to begin with heavy weights or resistance that can tire or injure muscles or joints, says Dr. Richard C. Becker, a professor of medicine at the University of Cincinnati College of Medicine. He's also director of the college's Heart, Lung and Vascular Institute.

These exercises are good for type 2 muscle fibers:

Longevity. A raft of research suggests that being physically active including engaging in strength and cardio training is associated with living longer.

A study published in 2019 in the journal BMJ suggests that middle-aged and older adults, including individuals with heart disease and cancer, "stand to gain substantial longevity benefits by becoming more physically active, irrespective of past physical activity levels and risk factors."

"When compared to one another, a person doing only cardiovascular training and no strength training would stand to improve longevity more than a person who only engages in strength training," Vigil says. "This would be ill-advised, however, since the two forms of exercise are complementary to one another. This is especially true for the aging population who depend on adequate strength and balance to prevent falls and complications resulting from fall-related injuries."

According to the Centers for Disease Control and Prevention, falls are the leading cause of injury and death among adults age 65 and older.

However, recent research shows that maintaining muscle mass as you age, for which you need strength training, is a leading indicator of how long you will live and how healthy those years will be. A 2017 Current Opinion in Clinical Nutrition & Metabolic Care study found that lean muscle mass even outperforms body mass index at gauging overall health.

Keep in mind that you don't have to run a marathon or log hours at the gym to benefit from increased physical activity. Walking, stretching and practicing yoga movements are all considered physical activity, Becker says.

Slideshow: The 50 all-time best exercises for weight loss (Courtesy: The Active Times)

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Differences in How Cardio and Strength Affect Your Health - msnNOW