Skip to Main Content

We have a new app!

Take the Access library with you wherever you go—easy access to books, videos, images, podcasts, personalized features, and more.

Download the Access App here: iOS and Android



After completing this chapter, you should be able to do the following:

  • Define strength, endurance, and power and indicate their relevance to health and skill of performance.

  • Discuss factors that determine levels of muscular strength.

  • Explain the physiological changes that occur which increase strength.

  • Explain why core stabilization exercises should be a part of all strength-training programs.

  • Demonstrate proper techniques for using progressive resistance exercise to develop strength and muscular endurance in specific muscle groups.

  • Discuss isometric and circuit training exercises as techniques for improving muscle strength.

  • Explain how functional fitness training exercises and plyometrics can be incorporated into strength-training programs.

  • Demonstrate various body-weight exercises that can be used for increasing muscular strength and endurance.


  • muscular strength

  • muscular endurance

  • power

  • concentric contraction

  • eccentric contraction

  • hypertrophy

  • atrophy

  • motor unit

  • myofilaments

  • core stabilization training

  • progressive resistance exercise

  • isometric exercise

  • isokinetic exercise

  • circuit training

  • functional strength training

  • plyometric exercise

  • body-weight exercise

Why Is Muscular Strength Important for Everyone?

The development of muscular strength is an essential component of fitness for anyone involved in a physical activity program. By definition, strength is the ability of a muscle to generate maximum force against some heavy resistance. The development of muscular strength may be considered as both a health-related and a performance-related component of physical fitness. Maintenance of at least a normal level of strength in a given muscle or muscle group is important for normal healthy living. Muscle weakness or imbalance can result in abnormal movement or gait and can impair normal functional movement. Muscle weakness can also produce poor posture, which can affect appearance. One of the most common health ailments in the United States is lower back pain. In most cases, lower back pain is related to lack of muscular fitness, especially lack of muscular strength in the abdominals and loss of flexibility of the hamstrings. (See Chapter 9 for more discussion of lower back pain.) Thus, strength training may play a critical role not only in fitness programs but also in injury prevention and rehabilitation.

muscular strength: the ability of a muscle to generate force against some resistance

How Are Strength and Muscular Endurance Related?

Muscular strength is closely associated with muscular endurance. Muscular endurance is the ability to perform repetitive muscular contractions against some resistance for an extended period of time. As we will see later, as muscular strength increases, there tends to be a corresponding increase in endurance. For example, suppose a person can lift a given weight 25 times. If that person's muscular strength increases by 10 percent through weight training, it is very likely that his or her maximal number of repetitions also would be increased because it is easier for the person to lift the weight. For most people, developing muscular endurance is more important than developing muscular strength because muscular endurance ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.