Strength Exercise: Everything You Need to Know

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Strength exercise, or resistance training, works your muscles by using resistance, like a dumbbell, barbell or your own body weight. This type of exercise increases lean muscle mass, which is particularly important for weight loss, because lean muscle burns more calories than other types of tissue. When people drop pounds, they can also lose muscle, so it's important to do resistance training to keep that muscle mass. It's also key to learn weightlifting for beginners before starting resistance training. 

"You can lose weight quickly [by] doing other stuff, but you're not going to keep it off [in the] long term if you don't maintain lean muscle mass," said Kelly Drew, an exercise physiologist with the American College of Sports Medicine.  [The Best Way to Keep Weight Off]

People also naturally lose muscle mass as they age, so resistance training is important for older adults. Having strong muscles can make it easier to do everyday activities, like gardening or taking your suitcase out of an overhead bin on an airplane, said Jason Schatzenpahl, a fitness specialist at CU Anschutz Health and Wellness Center in Aurora, Colorado.

Examples of strength exercises include:

  • Lifting weights
  • Using resistance bands
  • Using your body weight for resistance, by doing push-ups, pull-ups, crunches, leg squats or push-ups against a wall
  • Using weight machines at a gym

Benefits of strength exercises include:

  • Increased lean muscle mass (or prevention of its loss)
  • Increased bone density and reduced risk of osteoporosis
  • Increased metabolism to help with weight loss or weight maintenance
  • Increased muscle strength to make everyday activities easier
  • Lowered risk of injury (by allowing the muscles to better support the joints)

In addition, some of the benefits that are perhaps traditionally associated with aerobic exercise can also be gained by doing strength training. For example, a 2009 review study found that resistance training reduces people's blood sugar levels and improves sensitivity to the hormone insulin, which helps blood sugar get inside cells.

How much strength exercise do you need to do?

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The HHS' physical activity guidelines recommend doing resistance-training exercises at least two days per week. These exercises should work all of the major muscle groups in your body — your legs, hips, back, chest, abdomen, shoulders and arms.

(If you want to try some resistance training exercises, try some of the best exercises for shoulders.)

For each muscle group that you exercise, you should try to do at least eight to 12 repetitions of an activity (like lifting a weight), according to the Centers for Disease Control and Prevention. To get the benefits from the exercise, you need to work the muscles to the point where it's difficult for you to do another repetition, the CDC says.

But you shouldn't exercise the same muscle group two days in a row, because your muscles need time to recover, according to the National Institutes of Health. 

How can you avoid injury when doing strength training?

It's very important that you have the correct form and body position when you do resistance training. "If you do some of these exercises poorly, with bad technique, you can injure yourself," said said Dr. Edward Laskowski, co-director of the Mayo Clinic Sports Medicine Center in Rochester, Minnesota. You may need to work with a professional trainer, or watch exercise videos online, to make sure you use the correct technique.

If you're just starting out, you should use a light weight that you can lift or push at least eight times, the NIH says. Once it becomes easy to lift this weight, gradually add more weight. The American College of Sports Medicine recommends that when you are comfortable lifting a certain weight, you should increase the weight by about 2 to 10 percent, and then work on lifting this heavier weight until it again becomes comfortable.

Original article on Live Science.

Rachael Rettner

Rachael is a Live Science contributor, and was a former channel editor and senior writer for Live Science between 2010 and 2022. She has a master's degree in journalism from New York University's Science, Health and Environmental Reporting Program. She also holds a B.S. in molecular biology and an M.S. in biology from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Post and Scientific American.