TM-10-2

Evaluating Your Isotonic Muscular Endurance Squats Objective: To measure the muscular endurance of the quadriceps, hamstrings, gluteus maximum and minus and rhomboids‌the primary muscle being the quadriceps.

Age level: Age 16 through college level.

Reliability: Reliability coefficients range from .81 to .96.

Objectivity: An objectivity coefficient of .91 was reported by Ward (2003).

Validity: Face validity is generally accepted for this test.

Equipment: Squat rack, Olympic bar, collar and free weights.

Directions: The biomechanics for this exercise is exactly the same as those reported for the squat in the previous chapter.

Score: The subjects score is the maximum number of repetitions he can perform on the exercise without stopping.

Bench Press Objective: To measure the muscular endurance of the pectoralis major and minor, the triceps and the anterior deltoids.

Age level: Age 16 through college level.

Reliability: Reliability coefficients range from .89 to .96.

Validity: Face validity is generally accepted for this test.

Equipment: A bench, Olympic bar, collar and free weights.

Directions: The biomechanics for this exercise is exactly the same as those reported for the bench press in the previous chapter.

Score: The subjects score is the maximum number of repetitions he can perform on the exercise without stopping.

Military Press Objective: To measure the endurance of the anterior deltoids and triceps.

Age level: Age 16 through college level.

Reliability: Reliability coefficients range from .84 to .96.

Validity: Face validity is generally accepted for this test.

Equipment: An Olympic bar, collar and free weights.

Directions: The biomechanics for this exercise is exactly the same as those reported for the military press in the previous chapter.

Score: The subjects score is the maximum number of repetitions he can perform on the exercise without stopping.

Deadlift Objective: To measure the endurance of the quadriceps, hamstrings, gluteus maximum and minus and rhomboids‌the primary muscle being the quadriceps and the lower back.

Age level: Age 16 through college level.

Reliability: Reliability coefficients range from .89 to .96.

Validity: Face validity is generally accepted for this test. The test correlates .83 with total body endurance when it is used to evaluate elite athletes. (Cotton, Biasiotto, and Chissom 1974) Equipment: An Olympic bar, collar and free weights.

Directions: The biomechanics for this exercise is exactly the same as those reported for the deadlift in the previous chapter.

Score: The subjects score is the maximum number of repetitions he can perform on the exercise without stopping.

Free Weights versus Machines for Testing

As mentioned in the previous chapter considerable controversy has centered around the question of whether testing using free weights (barbells) or various types of weight machines (Nautilus, Universal, etc.) produces a greater validity for muscular strength and muscular endurance testing.

As previously indicated, a definitive answer to this question is not available. When comparing muscular endurance and strength scores obtained on various types of weight machines, little differences exist between variable-resistance machines and constant-resistance machines.

Also, as mentioned before, there are some major disadvantages and advantages of using machines. The major advantage of using machines is that they are relatively safe. They also require less skill; consequently, the measure is more objective than you will get when testing with free weights. In addition, machines require less time to change the weights, require fewer individuals to give the test, and the movement is the same for each subject being tested. The major disadvantage especially for a school setting is the high cost of the equipment.

With the aforementioned in mind let’s look at some of the test exercises that require machines.

Note that I have only presented exercise for muscle groups that were not cover in the free weight section. It should be noted that machines could be used for bench pressing, squats, incline bench presses, military presses etc.

Leg Press Objective: To measure the strength of the quadriceps.

Age level: Age 16 through college level.

Reliability: Reliability coefficients range from .90 to .98.

Validity: Face validity is generally accepted for this test.

Equipment: A leg press machine.

Directions: The biomechanics for this exercise is exactly the same as those reported for the leg press in the previous chapter.

Score: The subjects score is the maximum number of repetitions he can perform on the exercise without stopping.

Lat Pulldowns Objective: To measure the endurance of the latissimus dorsi.

Age level: Age 16 through college level.

Reliability: Reliability coefficients range from .90 to .98.

Validity: Face validity is generally accepted for this test.

Equipment: A lat machine or pulldown machine.

Directions: The biomechanics for this exercise is exactly the same as those reported for the lat pulldowns in the previous chapter.

Score: The subjects score is the maximum number of repetitions he can perform on the exercise without stopping.

Leg Curls Objective: To measure the endurance of the hamstrings.

Age level: Age 16 through college level.

Reliability: Reliability coefficients range from .89 to .98.

Validity: Face validity is generally accepted for this test.

Equipment: A leg curl machine.

Directions: The biomechanics for this exercise is exactly the same as those reported for the leg curls in the previous chapter.

Score: The subjects score is the maximum number of repetitions he can perform on the exercise without stopping.

Leg Extensions Objective: To measure the endurance of the quadriceps.

Age level: Age 16 through college level.

Reliability: Reliability coefficients range from .90 to .96.

Validity: Face validity is generally accepted for this test.

Equipment: A leg extension machine.

Directions: The biomechanics for this exercise is exactly the same as those reported for the leg extensions in the previous chapter.

Score: The subjects score is the maximum number of repetitions he can perform on the exercise without stopping.

Seated Calf Raises Objective: To measure the endurance of the gastronomes.

Age level: Age 16 through college level.

Reliability: Reliability coefficients range from .87 to .94.

Validity: Face validity is generally accepted for this test.

Equipment and materials: A seated calf machine.

Directions: The biomechanics for this exercise is exactly the same as those reported for the seated calf raises in the previous chapter.

Score: The subjects score is the maximum number of repetitions he can perform on the exercise without stopping.

Other Instruments Used to Measure Isotonic Muscular Endurance In addition to the use of free weights or weight machines, maximal isotonic muscular endurance can be measured using dynamometers. You remember what a dynamometer is, don’t you? You know that device capable of measuring force. Hand-grip and back-lift dynamometers have been used to evaluate grip endurance and back muscular endurance, respectively, for many years. Just to refresh your memory dynamometers operate in the following way. When force is applied to the dynamometer, a steel spring is compressed and moves a pointer along a scale. By calibrating the dynamometer with known weights, one can determine how much force is required to move the pointer a specified distance on the scale.

The advantages of the isotonic dynamometer as a measure of muscular endurance testing include low cost of equipment and the fact that force is dynamically applied, which may simulate sport-specific movements.

Grip Dynamometer

Objective: To measure the endurance of your hand grip.

Age level: Age 16 through college level.

Reliability: Reliability coefficients range from .90 to .98.

Validity: Face validity is generally accepted for this test.

Equipment and materials: Grip dynamometer.

Directions: The grip dynamometer is used to measure the grip muscular endurance of the hand. It has an adjustable handle to fit the size of the hand and a maximum needle indicator for ease of scoring. The scoring dial is marked off in kilograms, from 0 to 100. Once grip strength is ascertained, 50% of the individual’s 1-RM is determined. The grip dynamometer is then set at that level of resistance. The subject then performs as many repetitions as possible.

Score: The subject’s score is the maximum number of repetitions he can perform on the exercise without stopping.

Other considerations: At one time it was believed (like with the measurement of strength) that grip dynamometer scores correlated with total body muscular endurance. However, a prolific amount of research conducted over the past two decades clearly indicates that this is not the case.

Summary This brings up another important point. Tests such as the Isotonic Muscular Endurance Test devised

by Johnson in which push-ups, pull-ups, dips, and sit-ups are performed for the maximum number of repetitions you can complete are not valid instruments for measuring muscular endurance. First of all most of these measure are neither absolute nor relative. As mentioned, who do you think is going to do more pull-ups a person who weighs 300 pounds or a person who weighs 140 pounds…most likely the latter person is going to do more? The person who weighs 300 pounds might have greater relative muscular endurance in that particular exercise, but because he has to pull-up his own weight his muscular endurance in that particular exercise may not be apparent. The same is true of dips, sit-ups, and push-ups.

Also understand that absolute endurance and strength correlate so high that basically they are one and the same. In other words, absolute endurance is really a measure of strength… not endurance.

If you are using absolute endurance as a measure of muscular endurance, you are really using a strength test to measure muscular endurance. In short, absolute endurance is an invalid measure of muscular endurance especially if you are going to use these measures to compare students with one another.

Consequently, if you are going to measure muscular endurance you have to factor out strength. The best exercises used for evaluating muscular endurance would be relative measures.

Muscular endurance like muscular strength is body specific, meaning that you will have to measure each body part and muscle independently. There is no single test that correlates with total body

muscular endurance. Therefore, in order to measure total body muscular endurance, each muscle group would have to be tested independently.