Muscular Strength and Endurance

1. Muscular Strength and Endurance Chapter 4

3. Gives the body shape Protects internal organs Provides for movement Consists of more than 600 muscles Functions of the Musculoskeletal System

4. Gives form to the body Protects vital organs Consists of 206 bones Acts as a framework for attachment of muscles Designed to permit motion of the body The Skeletal System

5. Muscles: provide movement & generate heat. Ligaments: connect bone to bone; injury = sprain Tendons: connect bone to muscle; injury = strain Bones: protection & shape Anatomy

6. Degree of movement Synarthrosis – immovable joint (ex: the skull) Amphiarthrosis – slightly movable joint (ex: fibrocartilaginous disc between the vertebrae; ligament or membrane links the two bones such as scapula to the clavicle) Diarthrosis – freely movable joint (ex: hip or shoulder joint) Joints

7. Diarthrosis Joints

8. Examples of Diarthrosis Joints Ball and Socket Hinge

9. Erect standing position with all body parts, including the palms of the hands, facing forward; considered the starting position for body segment movements Standard Reference TerminologyAnatomical Reference Position

10. Superior (closer to the head) Inferior (farther away from the head) Anterior (toward front of body) Posterior (toward back of body) Medial (toward the midline of the body) Lateral (away from the midline) Proximal (closer to the center of the body) Distal (farther away from the center of the body) Superficial (toward the surface of the body) Deep (inside the body and away from the surface) Standard Reference TerminologyDirectional Terms

11. Basic Joint Articulations • Flexion • Extension • Abduction • Adduction • Pronation (elbow and forearm) • Supination (elbow and forearm)

20. Human Body Muscle Diagram

21. Because a single muscle usually does not act alone when it exerts tension in normal body movement, it acts as one member of the team of muscles that partially or wholly can control or contribute to the joint movement occurring. Therefore, it is convenient and adequate in most cases of gross muscular analysis to refer to the action of “groups of individual muscles” rather than trying to name each one that is or might acting. Muscle Groups

22. Examples of Muscle Groups • Elbow flexors/extensors • Knee flexors/extensors • Shoulder abductors/adductors • Shoulder flexors/extensors • Hip flexors/extensors • Hip abductors/adductors

23. Planes of Motion

27. Group 1: Lunges. Group 2: Standing broad jump. Group 3: Frisbee throw. Group 4: Underhand toss/pitch in softball. Group 5: Push-ups. Group 6: Shoulder press with barbells. Group 7: Free throws in basketball. Group 8: Bench press with straight bar. Group Activity

28. Identify the following: 1. Joint(s) involved in activity 2. Muscle group(s) involved in activity 3. Plane(s) of motion 4. Axis(es) of rotation Group Activity

29. Muscular strength = the amount of force a muscle can produce with a single maximum effort Muscular endurance = the ability of a muscle or group of muscles to remain contracted (sustain a level of muscular force) or to contract repeatedly Muscular Strength and Endurance

30. Muscles consist of many muscle fibers (cells) connected in bundles Muscle fibers are made up of myofibrils Strength training increases the number of myofibrils and the size of muscle fibers = hypertrophy Inactivity reverses the process = atrophy Muscle Physiology

31. Skeletal Muscle Tissue

32. Slow-twitch fibers Fatigue resistant Don’t contract as rapidly and forcefully as fast-twitch fibers Rely primarily on oxidative energy system Fast-twitch fibers Contract rapidly and forcefully Fatigue more quickly than slow-twitch fibers Rely more on non-oxidative energy system Muscle Fibers

33. Motor Units • Motor units (nerves connected to muscle fibers) are recruited to exert force

34. Motor Unit Recruitment

35. Increased muscle mass and size of muscle fibers Increased utilization and coordination of motor units Increased strength of tendons, ligaments, and bones Increased storage of fuel in and blood supply to muscles Improvements in blood fat levels and biochemical processes Physiological Effects of Strength Training

36. Improved performance of physical activities Injury prevention Improved body composition Enhanced self-image and quality of life Improved muscle and bone health with aging Prevention and management of chronic disease Benefits of Muscular Strength and Endurance

37. Muscular strength assessed by determining repetition maximum (1 RM), the maximum resistance that can be lifted once Muscular endurance assessed by counting the maximum number of repetitions of a muscular contraction Assessing Muscular Strength and Endurance

38. Static (isometric) exercise = muscle contraction without a change in the length of the muscle Dynamic (isotonic) exercise = muscle contraction with a change in the length of the muscle Concentric contraction = muscle applies force as it shortens Eccentric contraction = muscle applies force as it lengthens Types of Strength Training Exercises

39. Constant resistance = constant load throughout a joint’s range of motion Variable resistance = changing load to provide maximal resistance throughout a joint’s range of motion Eccentric loading = placing load on a muscle as it lengthens Plyometrics = sudden eccentric loading and stretching followed by a concentric contraction Speed loading = moving a load as rapidly as possible Isokinetic exercise = exerting force at a constant speed against an equal force Types of Dynamic Exercise

40. Isometric: muscle action that is performed against resistance at any point in a joint's range of motion, for periods of 5-10 seconds, and that produces no joint movement Modes of Exercise

41. Isotonic: alternating concentric and eccentric muscle activation that moves a body part through an arc of motion against resistance Modes of Exercise

42. Isokinetic: exercise that involves specialized equipment that provides "accommodating resistance" so that the joint moves at a constant angular velocity Modes of Exercise

43. Plyometric: exercise that requires eccentric activation of muscles against a resistance, followed by concentric activation Modes of Exercise

44. Choosing equipment: Weight machines versus free weights Resistance is provided by both types Exercise machines Safer, convenient, and easy to use Free weights Require more care, balance, and coordination Strength transfers to daily activities Workouts with resistance bands and stability balls also build strength Selecting Equipment

45. Frequency = days per week Intensity = amount of resistance Time = number of repetitions and sets Type = strength training exercises for all major muscle groups Applying the FITT Principle

46. American College of Sports Medicine recommends 2-3 days per week Allow 1 full day of rest between workouts Frequency of Exercise

47. Choose resistance based on your current fitness level and goals To build strength Lift heavy weights (80% of 1 RM) Perform a low number of repetitions To build endurance Lift lighter weights (40-60% of 1 RM) Perform a high number of repetitions For a general fitness program Lift moderate weights (70% of 1 RM) Moderate number of repetitions Intensity of Exercise: Amount of Resistance

48. To build strength and endurance, do enough repetitions to fatigue the muscles The heavier the weight, the fewer the repetitions (1-5) to fatigue = a program to build strength The lighter the weight, the higher the number of repetitions (15-20) to fatigue = a program to build endurance To build both strength and endurance, try to do 8-12 repetitions of most exercises Time of Exercise: Repetitions and Sets

49. Set = a group of repetitions followed by a rest period For general fitness, 1 set of each exercise is sufficient Doing more than one set will increase strength development Rest between sets Time of Exercise: Repetitions and Sets

50. Training for Strength versus Training for Endurance