Muscular strength and endurance

Muscular strength may be defined as the maximal force that can be generated against resistance by a muscle during a single maximal contraction. Muscular endurance is the ability to perform repeated isotonic or isokinetic muscle contractions or to sustain an isometric contraction without undue fatigue. Muscular endurance tends to improve with muscular strength thus training techniques for these two components are similar. Muscular strength and endurance are essential components of any rehabilitation program. Muscular power involves the speed with which a forceful muscle contraction is performed. The ability to generate force is dependent on the physical properties of the muscle, neuromuscular efficiency, as well as the mechanical factors that dictate how much force can be generated through the lever system to an external object. Hypertrophy of a muscle is caused by increases in the size and perhaps the number of actin and myosin protein myofilaments, which result in an increased cross-sectional diameter of the muscle. The key to improving strength through resis­tance training is using the principle of overload within the constraints of the healing process. Five resistance training techniques that can improve muscular strength are isometric exercise, progressive resistive exercise, isokinetic training, circuit training, and plyometric training. Improvements in strength with isometric exercise occur at specific joint angles. Progressive resistive exercise is the most common strengthening technique used by the sports therapist for reconditioning after injury.

1.1. Listen to the text “Muscular Strength and Endurance”.

1.2. Read and translate the text.

1.3. Answer the question on the text.

1. How may muscular strength be defined as? 2. What is muscular endurance?

3. What does muscular endurance tend to improve with? 4. Are these two components similar or not? 5. What is the ability to generate force dependent on? 6. By what is hypertrophy of a muscle caused? 7. What is the key to improve strength? 8. Which technique can improve muscular strength? 9. What kind of exercises is frequently used by the sports therapists?

1.4. Find English equivalents from the text for the following.

под определенным углом сгиба сустава, ключ, наиболее распространенная

техника, принцип сверхнагрузок, силовое совершенствование, упражнения с наращиванием сопротивления, круговая/комбинированнная тренировка, мышечная сила, в рамках требований лечебного процесса, вызывать /быть причиной, быть результатом /приводить к, вовлекать /включать, мощное мышечное сокращение, способность, выполнять, усталость, чрезмерный, определять, вести /иметь тенденцию к улучшению, повторяющийся, поддерживать /выдерживать, производить /генерировать, таким образом, схожий /подобный, физические свойства, эффективность, усилие, система рычагов, отдаленный, быть зависимым, гипертрофия, размер, количество, диаметр поперечного сечения, восстановление после травмы, выносливость

1.5. Substitute the italic words with those similar from the text.

1. Muscular strength may be determined as the maximal force that can be generated against resistance by a muscle during a single maximal contraction. 2. Muscular endurance is the ability to maintain an isometric contraction without undue fatigue. 3. Muscular endurance is supposed to improve with muscular strength. 4. Muscular strength and endurance are important parts of any rehabilitation program. 5. Muscular power includes the speed with which a forceful muscle contraction is performed. 6. The capability to create force depends on the physical qualities of the muscle, neuromuscular efficiency, as well as the mechanical aspects that define how much force can be generated through the lever system to a distant object. 7. The key to enhancing strength by means of resistance training is applying the principle of overload in the limits of the healing process. 8. Improvements in strength with isometric exercise happen at particular joint angles. 9. Progressive resistive exercise is the most wide-spread strengthening technique used by the sports therapist for rehabilitation after injury.

1.6. Complete the sentences with logical endings.

1. Muscular strength may be defined as....

2. Muscular endurance is the ability to perform....

3. Muscular power involves....

4. The ability to generate force is dependent on....

5. Hypertrophy of a muscle is caused by....

6. The key to improving strength through resistance training is....

7. Five resistance training techniques that can improve muscular strength are....

8. Improvements in strength with isometric exercise occur at....

9. Progressive resistive exercise is the most common strengthening technique for....

1.7. Open the brackets and use the verbs in a right tense and voice form.

1. Muscular strength (to be) proportional to the cross-sectional diameter of the muscle fibers. 2. The greater the cross-sectional diameter or the bigger a particular muscle, the stronger it (to be), and thus the more force it (to be) capable of generating. 3. The size of a muscle (to tend) to increase in cross-sectional diameter with weight training. 4. This increase in muscle size (to refer) to as hypertrophy. 5. Conversely a decrease in the size of a muscle (to refer) to as atrophy. 6. Strength (to be) a function of the number and diameter of muscle fibers composing a given muscle. 7. The number of fibers (to be) an inherited characteristic, thus a person with a large number of muscle fibers to begin with (to have) the potential to hypertrophy to a much greater degree than (to do) someone with relatively few fibers.

MUSCLE ATTACHMENTS       Effort arm Effort arm A B The position of attachment of the muscle tendon on the lever arm can affect the ability of that muscle to generate force. В should be able to generate greater force than A because the tendon attachment on the lever arm is closer to the resistance

1.8. Use appropriate prepositions in gaps.

1. Strength is also directly related to the efficiency … the neuromuscular system and the function … the motor unit … producing muscular force. 2. As will be indicated later in this chapter, initial increases … strength … the first 8 to 10 weeks … a weight-training program can be attributed primarily to increased neuromuscular efficiency. 3. Strength training will increase neuromuscular efficiency … three ways: there is an increase … the number … motor units being recruited, there is an increase … the firing rate … each motor unit, and there is increased synchronization … motor unit firing. 4. Strength … a given muscle is determined not only … the physical properties … the muscle but also … biomechanical factors that dictate how much force can be generated through a system … levers to an external object.

1.9. Insert articles if necessary.

1. If we think of … elbow joint as one of these lever' systems, we would have … biceps muscle producing flexion of this joint. 2 … position of attachment of … biceps muscle on … forearm will largely determine how much force this muscle is capable of generating. 3. If there are two athletes, A and B, and A has … biceps attachment that is closer to … fulcrum (… elbow joint) than B, then A must produce … greater effort with … biceps muscle to hold … weight at a right angle because the length of … effort arm will be greater than with B.

Muscle contraction. Muscles contract when an electrical impulse from the central nervous system causes the myofilaments in a muscle fiber to move closer together.

1.10. Ask questions to the italicized words.

1. The length of a muscle determines the tension that can be generated. 2. By varying the length of a muscle, different tensions may be produced. 3. This length-tension relationship is illustrated in Figure above. 4. At position A in the curve, the interaction of the crossbridges between the actin and myosin myofilaments within the sarcomere is at maximum. 5. Setting a muscle at this particular length will produce the greatest amount of tension. 6. At position A the muscle is shortened, and at position С the muscle is lengthened. 7. In either case the interaction between the actin and myosin myofilaments through the crossbridges is greatly reduced, thus the muscle is not capable of generating significant tension.

1.11. Fill in the gaps with words from a box.