Muscle Fitness: Muscular Endurance and General Muscle Fitness Information

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In this chapter… Activity 1 Homemade Weights Lesson 12.1 Improving Muscular Endurance Self-Assessment Muscular Endurance Lesson 12.2 Muscle Fitness Taking Charge Managing Time Self-Management Skill Managing Time Activity 2 Muscular Endurance Exercise Circuit

Activity 1 Homemade Weights In chapter 11 you learned how to properly perform free-weight exercises to build muscular endurance and strength. If your school has weights and keeps the weight room open for recreational use, you can perform weight training at school. Of course, you can buy weights or join a health club so that you have the equipment to do free-weight training, but either can be expensive. An alternative is to use homemade weights made of bottles filled with water and a broomstick or piece of plastic pipe. If done properly, this alternative can be a safe and inexpensive way to do freeweight training.

Lesson

12.1

Improving Muscular Endurance Lesson Objectives After reading this lesson you should be able to 1. Describe the differences among muscular endurance, cardiovascular fitness, and muscular strength. 2. Describe benefits of good muscular endurance. 3. Explain the FIT formula for building muscular endurance. 4 . Describe several guidelines for building muscular endurance.

Lesson Vocabulary

Cardiovascular fitness.

electromyogram (EMG) (p. 202) www.fitnessforlife.org/student/12/1

In this lesson, you will learn about muscular endurance and how it improves your health and affects your life. You will also learn about the FIT formula for building muscular endurance. In the last chapter you learned that muscular endurance, one part of muscle fitness, is different from strength, the other part of muscle fitness. It is also important to know the difference between cardiovascular fitness and muscular endurance.

Muscular Endurance Versus Cardiovascular Fitness Cardiovascular fitness is the ability of the heart, lungs, and blood vessels to function efficiently during vigorous activity. The cyclist in the first picture needs good cardiovascular fitness to ride for a long time. Cardiovascular fitness is dependent on the heart and blood vessels to deliver blood. It is very general in nature rather than specific to one area of the body as is the case for muscle fitness. Good cardiovascular fitness allows the entire body to function. Muscular endurance is the ability to contract muscles many times without tiring or to hold one contraction for a long time. Muscular endurance is dependent on the ability of your muscle fibers to keep working with-

Muscular endurance.

out getting tired. You can have good muscular endurance in one part of the body, such as the legs, without having good muscular endurance in another part of the body, such as the arms. The person in the second picture needs good muscular endurance to be able to

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chop wood. If she has not developed good muscular endurance in the arms, she will not be able to continue chopping for a very long time even if she has good cardiovascular endurance.

Benefits of Muscular Endurance Muscular endurance exercise improves appearance, fitness, and physical and mental health. Good muscular endurance enables people to work longer without getting tired. Those with good muscular endurance find it easier to maintain good posture. In addition, they are less likely to have backaches, muscle soreness, and muscle injuries. Muscular endurance training also increases your lean body mass and decreases fat. This improvement in body composition can help you look and feel better. Muscular endurance developed through physical activity decreases heart rate, helping reduce the risks of cardiovascular disease. Resistance training, whether done for endurance or strength, also strengthens your bones.

FITfacts

Many teens wear backpacks. To carry a backpack effectively, you need adequate strength and muscular endurance. In a typical year the U.S. Consumer Product Safety Commission reports more than 6,000 backpack related injuries, mostly to youth. In addition to improving your muscle fitness, you can do several things to reduce your risk of injury from wearing a backpack (see photo).

FIT Formula for Muscular Endurance The frequency, intensity, and time recommended for muscular endurance are shown in table 12.1. You may either do calisthenics, in which you lift the weight of your body parts, or work against the resistance of weights or machines. These kinds of exercises involve isotonic muscle contractions. It is also possible to build muscular endurance using isometric contractions. In life you have to contract posture muscles for long periods during the day. When holding things, such as a serving tray, you need extended isometric contractions. In general, however, performing isometric exercises should help you perform most isotonic exercise that you will encounter in daily life. Also it is hard to get motivated to hold isometric contractions for extended periods of time. For these reasons only isotonic exercise is included in the table. Isometric contractions can be used successfully to test your muscular endurance because it is not hard to get motivated to do one repetition and you can easily see how well you have performed. The trunk lift you performed in the self-assessment for chapter 5 is an example. Muscular endurance exercises can be done more frequently than strength exercises. Strength exercises are typically done only 2 to 3 times a week. Muscular endurance exercises can be done on most days of the week because they do not require maximal contractions. Like cardiovascular fitness exercise, it is probably best to take at least one day a week off from exercise. Because the resistance is lower than for strength, multiple sets of muscular endurance exercises are often performed.

FITfacts

The electromyogram (EMG) is a machine researchers use to determine how hard a muscle contracts. Small contractions such as those for muscular endurance show a low muscle action wave, and harder contractions such as those for strength show a larger muscle action wave.

www.fitnessforlife. org/student/12/2

Table 12.1 Muscular Endurance Target Zones (Isotonic) Threshold

Target zone

Frequency

3 days/wk

3-6 days/wk

Intensity

20% 1RM

20-55% of 1RM

Time

1 set of 11-25 reps for each exercise

1-3 sets of 11-25 reps for each exercise

Rest 2 minutes between sets.

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FIT

facts

Rather than doing more than 25 repetitions of an exercise in one set, several sets of 25 repetitions or less is recommended. When people perform calisthenics with more than 25 repetitions in a set, they often perform the exercises incorrectly.

Circuit Training Programs for Muscular Endurance Muscular endurance programs include calisthenics and resistance training. Sports, active aerobics, and active recreation are also good for developing muscular endurance. You learned about circuit training earlier. It is included again here because it is one of the most popular forms of muscular endurance training. You can easily do a muscular endurance circuit with little or no equipment or with expensive machines. As explained in chapter 8, circuit training involves moving from one exercise station to another with short breaks for changing stations. At each station, you perform a different exercise using the FIT formula described earlier. Many different exercise circuits are provided in this book, including one emphasizing muscular endurance at the end of this chapter. Later you will get the opportunity to develop your own circuit training program. www.fitnessforlife.org/student/12/3

Guidelines for Muscular Endurance Exercise To avoid injury and increase your enjoyment of the activities, follow these guidelines when exercising for muscular endurance: Always warm up and stretch

gently before exercising. Breathe normally while exercising. Holding your breath may cause an abdominal hernia or cause you to black out. Start with low-intensity exercises and progress slowly. Too many reps and sets too soon will cause muscular soreness and slow your progress.

Use good body mechanics and correct technique. To work a specific set of muscles, the movement must be done exactly right or you may actually be working the wrong set of muscles or straining other body parts. Take your time and work rhythmically. Always move through a full range of motion. This will prevent loss of flexibility. (See chapter 10 for more on flexibility and range of motion.) Avoid working the same muscles in two consecutive exercises. Exercise each specific muscle group. If you do not know how to isolate a specific muscle, ask your instructor about it. Most people tend to exercise their chest (pectoral), biceps, and other muscles on the front of the body, while neglecting the muscles on the back. Include exercises for the triceps on the backs of your arms, the hamstrings on the backs of your legs, and the muscles between your shoulder blades. Vary your exercise routine to avoid boredom. Many ways exist to exercise the same muscles effectively. Consider multiple sets. Good muscular endurance is best achieved by doing multiple sets rather than doing one set of repetitions to exhaustion.

Lesson Review 1. What are the differences among muscular endurance, cardiovascular fitness, and muscular strength? 2. What are the benefits of good muscular endurance? 3. What is the FIT formula for muscular endurance? 4. What are some of the guidelines for performing muscular endurance exercises?

FITNESS Technology

In recent years high-tech physical fitness tests that were formerly only available in laboratories have become available in schools and fitness centers. One assessment system (called TriFit) can be used to test multiple parts of fitness including blood pressure, flexibility, body composition, cardiovascular fitness, and muscle fitness. If your school has a high-tech system such as TriFit, you can use it to test various aspects of fitness to compare against your self-assessments done in this book. It is important to learn self-assessments that you can do at home in addition to high-tech tests because you can do self-assessments at home even when high-tech equipment is not available.

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Self-Assessment

Muscular Endurance Many tests can help you evaluate your muscular endurance, but the best ones assess your body’s large muscles. In this self-assessment you will perform some isotonic and some isometric tests. To evaluate your muscular endurance, follow these directions: Warm up before doing these assessment

Table 12.2

activities.

Write on your record sheet the number of times you complete each test. Check "yes" if you could do the test as long or as many times as indicated. Check "no" if you could not. If you cannot pass all the tests, you need to work on muscular endurance. Look up your rating on table 12.2 and

Rating Chart: Muscular Endurance Fitness rating

Number of tests passed

Good

5

Marginal

3 or 4

Low