Muscular Strength, Endurance, and Power Chapter 13 Muscular Strength, Endurance, and Power

Chapter Objectives After completing this chapter, you should be able to 1. Define muscular strength, dynamic strength, static strength, dynamic and static muscular endurance, and power. 2. State why muscular strength, endurance, and power should be measured. 3. Measure muscular strength, endurance, and power. 4. Prescribe activities to improve muscular strength, endurance, and power.

Muscular Strength, Dynamic Strength, and Static Strength Muscular strength is the ability of a muscle or muscle group to exert maximum force. Dynamic strength is the force exerted by a muscle group as a body part moves (isotonic strength). Static strength is the force exerted against an immovable object; movement takes not take place (isometric strength). Both types of strengths are best measured by tests that require one maximum effort.

Dynamic and Static Muscular Endurance Dynamic muscular endurance is the ability of a muscle or muscle group to resist fatigue and to make repeated contractions against a defined submaximal resistance Static muscular endurance is the ability to maintain a certain degree of force over time. High-resistance, low-repetition program or low-resistance, high-repetition program? Must have some strength to develop endurance.

Muscular Power Muscular power is the ability to generate maximum force in the fastest possible time; ability to release maximum muscular force in an explosive manner. Power equal to the product of force times velocity. Force generated by muscular strength; velocity is the speed the force is used. Power usually measured by some type of jump, throw, or charge (vertical jump, shop put, or a charge at a blocking sled).

Why Measure Muscular Strength, Endurance, and Power? 1. Strong muscles help protect the joints; less susceptible to sprains, strains, and other injuries. 2. Necessary for good posture (abdominal muscles, round shoulders, and low back pain). 3. Perform routine tasks more efficiently. 4. Increase changes for success in sports. 5. Decline in muscle strength can affect functions such as agility, balance, and cordination

Why Measure Muscular Strength, Endurance, and Power? Muscular Endurance 1. Perform daily tasks better; prevent end-of-day fatigue. 2. Maintain good posture; decrease likelihood of back problems and muscular injury while performing routine tasks. Muscular Power Often a characteristic of a good athlete, but is rarely necessary for performing daily tasks.

Tests of Muscular Strength and Endurance In laboratory and rehabilitation setting, dynamometers, cable tensiometers, and electromechanical instruments may be used to measure muscular strength and endurance. Tests with Weight-Training Equipment Handgrip, knee flexion, foot placement, and all other considerations that may influence test performance must be standardized. Test must also be standardized for motivational considerations.

Tests of Muscular Strength and Endurance Conduct warm-up, avoid overworking, and observe safety precautions. Dynamic strength measured with one repetition maximum (1-RM). Relationship exists between body weight and weight lifted; maximum weight that can be lifted should be interpreted in relation to individual’s weight. Major muscle groups may be tested with the bench press standing press, arm curls, and leg press. Table 13.1 reports optimal strength values for these lifts.

Tests of Muscular Strength and Endurance Relative muscular endurance test - performer works with weight that is proportionate to the maximum strength of a particular muscle group or to body weight Absolute muscular endurance test - all performers work with the same amount of weight (the weight has no relationship to maximum strength or body weight of the test performer)

Tests of Muscular Strength and Endurance In a test for muscular endurance, weight should be lifted and returned without jerky movements. A 3-second cadence may be used to encourage continuour, smooth movement. A fixed percentage of 70% of the maximum strength may be used to test muscle endurance. Health fitness – should be able to perform 12 to 15 repetitions of each of the lifts tested Competitive athlete – should be able to perform 20 to 25 repetitions

1-Repetition Maximum (RM) Bench Press Test Test objective. Measure strength of arm extension muscles. Age level. Twenty through sixty-plus. Validity. Research shows 1-RM bench press is best weight lifting test for predicting total dynamic strength. Norms. Table 13.2 Scoring. Ratio; divide maximum weight lifted by performer’s weight in pounds. Free weight equipment preferred over Universal or Nautilus equipment.

1-Repetition Maximum (RM) Leg Press Test Test objective. Test strength of lower leg extension muscles. Age level. Twenty through sixty-plus. Face validity Norms. Table13.3 Scoring. Ratio; divide maximum weight pressed by performer’s weight in pounds.

YMCA Bench Press Test Test objective. Test dynamic muscle endurance of upper arm and shoulder girdle. Age level. Eighteen through 65-plus. Equipment. Metromone, 35-pound barbell, 80-pound barbell, and weight bench. Norms. Table 13.4 Females use 35-pound barbell and males use 80-pound barbell. 30 repetitions per minute.

Sit-Ups Test (Strength) Test objective. To measure strength of abdominal and trunk flexion muscles Age level. Twelve through college-age. Face validity; reliability and objectivity coefficients reported. Figure 13.1 illustrates the test. Johnson and Nelson (1986) provide norms for college students.

Sit-Ups Test (Endurance) Test objective. To measure abdominal strength and endurance Age level. Five through adulthood. Logical validity; reliability coefficient reported. Three types of sit-ups tests may be administered – arms crossed on chest, hands interlocked behind neck, or hands cupped behind ears . Figures 13.2 and 13.3 illustrated first two tests. Tables 13.5, 13.6, and 13.7 report norms.

Abdominal Curls Test objective. To measure abdominal strength and endurance. Age level. Five through adulthood. Logical validity; reliability not reported. Table 13.8 reports norms for ages eighteen through thirty.

One Minute Curl Up Test Test objective. Measure abdominal strength and endurance. Age level. Five through sixty-plus. Face validity. Administered in same way as abdominal curl except test performer’s feet are held in place. Table 13.9 provides norms.

Pull-Ups Test for Strength Test objective. To measure arm and shoulder girdle strength. Age level. Twelve through college-age. Face validity; reliability and objectivity coefficients reported. Use weight plates and chair. Johnson and Nelson provide norms for college males.

Pull-Ups Test for Endurance Test objective. To measure arm and shoulder girdle strength and endurance. Age level. Nine through college-age. Face validity; reliability coefficient reported. Repeat pull-ups as many times as possible. Table 13.10 reports norms for males, ages nine through seventeen-plus.

Modified Pull-Ups for Endurance Test objective. To measure arm and shoulder girdle endurance. Age level. Ten through college-age. Face validity; reliability not reported. No norms reported. Figure 13.4 illustrates test

Baumgartner Modified Pull-Ups Test Test objective. To measure arm and shoulder girdle, endurance, or both. Age level. Elementary through college. Face validity and construct validity; reliability coefficient reported. Figure 13.5 illustrates test. Table 13.11 reports norms for ages six through college-age.

Modified Pull-Ups Test Test objective. To measure upper body muscular strength and endurance. Age level. Five through eighteen. Figures 13.6a and 13.6b illustrate test. No norms reported.

Flexed-Arm Hang Test objective. To measure arm and shoulder girdle endurance. Age level. Nine through college-age. Face validity; reliability and objectivity coefficients reported. Table 13.12 reports female norms for ages nine through seventeen-plus.

Dip Test for Strength Test objective. To measure arm and shoulder girdle strength. Age level. Twelve through college-age. Face validity; reliability and objectivity coefficients reported. Johnson and Nelson (1986) provide norms for college males.

Dips Test for Endurance Test objective. To measure arm and shoulder girdle endurance. Age level. Ten through college-age. Face validity; reliability coefficient reported. No norms reported.

Push-Ups Test objective. To measure arm and shoulder girdle endurance. Age level. Ten through adulthood. Face validity; reliability not reported; objectivity coefficient reported. Table 13.13 reports norms for males ages twenty through sixty-nine.

Modified Push-Ups Test objective. To measure arm and shoulder girdle endurance. Age level. Ten through adulthood. Face validity; reliability coefficient reported. Table 13.13 reports norms for females ages twenty through sixty-nine; Canadian Physical Activity Fitness and Lifestyle Appraisal also includes norms. Figure 13.7 illustrates test

Tests of Muscular Power Two types of muscular power may be measured : athletic power and work power. Athletic power – distance the body or an object can be propelled through space Work power – extraneous movements are controlled or eliminated, so that maximum effort must be put for by muscle groups being tested. Only two athletic power tests presented.

Vertical Jump Test objective. To measure explosive leg power. Age level. Nine through adulthood. Validity, reliability, and objectivity coefficients reported. Table 13.14 reports norms for ages ten through seventeen-plus and Table 13.15 reports norms for ages twenty through fifty-nine.

Standing Broad Jump Test objective. To measure explosive leg power. Age level. Six through college-age. Face validity; reliability coefficient reported. Table 13.16 reports norms for ages nine through seventeen-plus.

Exercises to Develop Muscular Strength and Endurance The following guidelines should be observed when performing exercises to develop muscular strength and endurance. Perform stretching and warm-up exercises before attempting muscular effort. Perform the exercises that provide a mild overload first and gradually progress to the more difficult ones. Unless otherwise indicated, begin with ten repetitions and add two or three repetitions each week until the desire number is reached. Perform the exercises 3 to 5 days per week.

Exercises to Develop Muscular Strength and Endurance Exercises to develop muscular strength and endurance are described in text. The exercises are for the: Posterior upper arms, shoulders, chest, and upper back Anterior upper arms, shoulders, chest, and upper back Abdomen Lateral trunk Lower back and buttocks Lateral hips and thighs Upper legs Lower legs