Exercise experts have long emphasized the importance of cardiovascular fitness. Other physical fitness factors, such as muscle strength and flexibility, were mentioned almost as an afterthought. As more was learned about how the body responds to exercise, however, it became obvious that these other factors are vital to health, wellness, and overall quality of life. Muscles make up more than 40% of your body mass. You depend on them for movement, and, because of their mass, they are the site of a large portion of the energy reactions (metabolism) that take place in your body. Strong, well-developed muscles help you perform daily activities with greater ease, protect you from injury, and enhance your wellbeing in other ways.

As described in Chapter 2, muscular strength is the ability to generate force during a maximal effort; muscular endurance is the ability to resist fatigue while holding or repeating a muscular contraction. This chapter explains the benefits of strength training (also called resistance training) and describes methods of assessing muscular strength and endurance. It then explains the basics of weight training and provides guidelines for setting up your own strength training program.

After reading this chapter, you should be able to Describe the basic physiology of muscles and how strength training affects muscles

Define muscular strength and endurance and describe how they relate to wellness

Explain how muscular strength and endurance can be assessed

Apply the FITT principle to create a safe and successful strength training program

Describe the effects of supplements and drugs that are marketed to active people and athletes

Explain how to safely perform common strength training exercises using free weights and weight machines