Understanding Muscular Strength

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Muscular strength refers to the amount of force a muscle can produce with a single maximal effort. The size of your muscle fibers and the ability of nerves to activate muscle fibers are related to muscle strength. It is measured during muscular contraction. Building muscle strength helps with body alignment, makes performing everyday actions easier, and increases metabolism.

What Is Muscular Strength?

You might think that muscular strength is simply how strong you are: How much you weight you can carry, how many pounds you can lift at the gym, or how many push-ups you can do during a workout. But the true definition of muscular strength is a little more complicated.

According to the American Council on Exercise (ACE), muscular strength is the ability to generate the maximal amount of muscle force while performing a particular exercise. But there are other factors that affect how strong you are and how much strength you have to complete daily chores or exercises. ACE provides definitions for these terms that are related to muscular strength:

  • Muscular endurance: The ability to produce and sustain muscle force over a certain period of time.
  • Muscular power: The ability to generate enough force to move weight in the shortest amount of time possible.

For example, the number of push-ups you can do in one minute depends on your muscular strength, but also on your muscular power and muscular endurance.

What happens in your body to produce the effect of strength relies on several factors. The size of the muscle and the ratio of fast-twitch and slow-twitch fibers in that muscle is one component.

Then the neural connection is key, as the motor neurons must be coordinated in their firing in order to signal the muscle fibers to contract at the same time. Strength also relies on the muscle having good support for the movement of the joint, including the health of the joints, bones, ligaments, and tendons.

Muscle-Strengthening Exercise Recommendations

The 2018 Physical Activity Guidelines for Americans from the U.S. Department of Health and Human Services recommends:

  • Children and adolescents: Muscle-strengthening physical activity at least three days per week.
  • Adults and older adults: Muscle-strengthening activities that are moderate or high intensity, involving all major muscle groups, two or more days per week.

Measuring Muscular Strength

The one-repetition maximum (1RM) test is the standard test used to measure muscle strength. During a 1RM test, an exerciser performs one repetition of a single exercise to see how much weight he or she can lift using correct lifting technique. There is a protocol to conduct this test, which is usually done with the bench press for upper body strength and the leg press for lower body strength.

In physical therapy, a therapist may measure a client's muscle strength in two ways. In manual muscle testing, the client resists the pressure exerted by the therapist to push a body part (such as your arm) in a specific direction. This is graded on a five-point scale. A dynamometer device can also be used, with the client pressing on it to exert a force that is then measured in pounds or kilograms.

Improving Muscle Definition and Strength

The best way to build muscle strength is to participate in a program of resistance training. Some people call it strength training or "weightlifting." But you don't have to lift weights to improve your muscles. You can do simple bodyweight exercises at home to build muscle and build strength.

Strength training improves both the size of your muscle fibers and the ability of your nerves to communicate with the muscles. So as your muscles get bigger with resistance training (muscle hypertrophy) they also become more coordinated and better able to perform movements that require strength.

How long does it take to build muscle strength? After three to four weeks of resistance training or strength training, you'll probably notice that your muscles get stronger. In addition, you may notice greater muscle definition. That is, your muscles become "defined" and easier to see on your body.

But muscle definition also depends on your level of body fat. If your muscles get bigger but you still carry too much fat, you may not see sculpted muscles on your body. To improve both muscle definition and muscular strength you need to combine dietary changes to lose fat with a resistance training program to build muscle.

Getting the Right Start

Before you get started with strength training, talk to your health care provider to make sure there aren't restrictions or modifications that you should follow to stay safe. If you are new to training, ask for help. A few sessions with a qualified trainer can help you to get your program off to a strong start for lasting results.

Benefits of Building Muscular Strength

When you improve muscular strength and muscular definition, you enjoy many different benefits, especially if you are trying to lose weight—and you don't have to be an expert bodybuilder to take advantage of them. Strength training provides benefits for exercisers of all levels.

When you include strength training in your exercise program, you build lean muscle mass and improve your metabolism. Having stronger muscles will also help you to move through your daily activities and burn more calories with greater ease.

A Word From Verywell

Exercise of any kind is important for good health and to maintain healthy body weight. But if you do strength or resistance training two to three times per week, you build strong muscles to stand taller, burn more calories, and improve the quality of your daily activities and movement.

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