1. Muscular Strength and Endurance
Chapter 8

2. Test your knowledge
For women, weight training typically results in which of the following?
Bulky muscles
Significant increases in body weight
Improved body image
C. Because the vast majority of women have low levels of testosterone, they do not develop large muscles or gain significant amounts of weight in response to a moderate weight training program. Men have higher levels of testosterone, so they can build large muscles more easily.

3. Test your knowledge
To maximize strength gains, it is a good idea to hold your breath as you lift a weight. True or False?
FALSE. Holding one’s breath while lifting weights, called the Valsava maneuver, can significantly (and possibly dangerously) elevate blood pressure; it also reduces blood flow to the heart and may cause faintness. You should breathe smoothly and normally while weight training. Some experts recommend that you exhale during the most difficult part of each exercise.

4. Test your knowledge
Regular strength training is associated with which of the following benefits?
Denser bones
Reduced risk of heart disease
Improved body composition
Fewer injuries
ALL FOUR. Regular strength training has many benefits for lifetime wellness for both men and woman.

5. Muscular strength and endurance
Muscular strength amount of force a muscle can produce with a single maximum effort.
Muscular endurance  ability to resist fatigue while holding or repeating a muscular contraction.
40% of your body mass is muscle
You depend on them for movement
Site of large portion of energy reactions (metabolism)
Strong, well developed muscles help you perform daily activities with greater ease, protect you from injury and enhance your well being.

6. Muscle physiology Myofibril  protein structure Muscle fibers (cells)
Fascicles  bundle of fibers
Connective tissue
Muscle  bundle of fascicles
Tendons  join muscles to bone
Nerves  transmit impulses to the brain

7. Types of muscle fibers Slow – twitch fibers Fast – twitch fibers
Contract slowly
Depend on aerobic (oxidative) energy system
Fatigue resistant
Fast – twitch fibers
Contract rapidly and forcefully
Fatigue more quickly
Depend more on anaerobic (nonoxidative ) energy system.
Most muscles contain a mixture of slow-twitch and fast-twitch fibers.

8. The type of fiber that acts during a particular activity depends on the type of work required.
Endurance activities slow-twitch fibers
Strength and power activities  fast-twitch fibers

9. Motor units Made up of a nerve connected to a number of muscle fibers
The number of muscle fibers in a motor unit varies from two to hundreds depending on the amount of strength required.
Small motor units contain slow- twitch fibers
Large motor units contain fast- twitch fibers
Strength training improves the body’s ability to recruit motor units (muscle learning)

10. Benefits of muscular strength and endurance
Improved performance of physical activities
A person with improved muscular strength and endurance can perform everyday tasks with ease.
Allows you to achieve high levels of performance in sports.
Improves oxygen consumption

11. Benefits of muscular strength and endurance
Injury prevention
Enables you to maintain good posture
Encourages proper body mechanisms during everyday activities such as walking and lifting
Proper alignment
Makes tendons, ligaments and cartilage cells stronger and less susceptible to injury.

12. Benefits of muscular strength and endurance
Improved body composition
Strength training improves body composition by increasing muscle mass
Helps with losing fat because metabolic rate is related to muscle mass.
Increases muscle temperature, which in turn slightly increases the rate at which you burn calories.

13. Benefits of muscular strength and endurance
Enhanced self-image and quality of life
Provides stronger, firmer-looking muscles and a toned, healthy-looking body
In men, larger muscles combine with high levels of the hormone testosterone for a strong tissue building effect.
Improves quality of life by increasing energy, preventing injuries, and making daily activities easier and more enjoyable.

14. Benefits of muscular strength and endurance
Improved muscle and bone health with aging
Good muscular strength helps people live healthier lives
Prevents sarcopenia  loss of muscle mass
Maintains motor nerve connections and the quickness of muscles.
Lessens bone loss even if its taken up later in life.

15. Benefits of muscular strength and endurance
Prevention of chronic disease
Prevents and manages both CVD and diabetes by
Improving glucose metabolism
Increasing maximal oxygen consumption
Reducing blood pressure
Increasing HDL cholesterol and reducing LDL cholesterol.

16. Assessing muscular strength and endurance
Muscular strength is assessed by measuring the maximum amount of weight a person can lift one time.
This single maximum effort is called repetition maximum (RM)
It can also be estimated by doing multiple repetitions with a sub-maximal (lighter) weight.
Muscular endurance
Assessed by counting the maximum number of repetitions of a muscular contraction a person can do (push-ups) or the maximum amount of time a person can hold a muscular contraction (flexed-arm hang)

17. Creating a successful strength training program
When muscles are stressed by a greater load than they are used to, they adapt and improve their function.
The type of adaptation depends on the stress applied
Strengthening exercises are classified as:
Static exercise
Dynamic exercise

18. Static exercise (isometric)
Involves muscle contraction without a change in the length of the muscle or the angle in the joint on which the muscle acts
Useful in strengthening muscles after an injury or surgery
Used to overcome weak points in an individual’s range of motion.
Recommended to hold an isometric contraction maximally for 6 seconds (5 – 10 repetitions)

19. Dynamic exercise (isotonic)
Involves muscle contraction with a change in the length of the muscle
Important for developing strength that can be transferred to other forms of physical activity
Two types
Concentric muscle contraction: occurs when the muscle applies enough force to overcome resistance and shortens as it contracts.
Eccentric muscle contraction: occurs when the resistance is greater than the force applied by the muscle and the muscle lengthens as it contracts.

20. Dynamic exercise techniques
Constant resistance exercise
Uses a constant load throughout a joint’s entire range of motion
There are points in a joint’s range of motion where the muscle controlling the movement is stronger and points where it is weaker.
Variable resistance exercise
The load is changed to provide maximum load throughout the entire range of motion.
Uses machines that place more stress on muscles at the end of the range of motion. (Nautilus pull-over machine)

21. Dynamic exercise techniques
Eccentric (plyometric) loading
Involves placing a load on a muscle as it lengthens.
The muscle contracts eccentrically in order to control the weight.
Plyometrics
A sudden eccentric loading and stretching of muscles followed by a forceful concentric contraction

22. Dynamic exercise techniques
Speed loading
Involves moving a weight as rapidly as possible in an attempt to approach the speeds used in movements like throwing a softball or sprinting
Isokinetic
Involves exerting force at a constant speed against an equal force exerted by a special strength training machine.

23. Static vs. Dynamic Exercise
Requires no equipment
Build strength rapidly
Useful for rehabilitation injured joints
Have to be performed at several different angles for each joint to improve strength throughout the joint’s entire range of motion
Can be performed without equipment or with equipment
Excellent for building strength and endurance
Tend to build strength through a joint’s full range of motion

24. Weight machines vs. free weights
Exercise machines
Free weights
Advantages
Disadvantages
Are save and convenient
Don’t require spotters
Don’t require lifter to balance bar
Provide variable resistance
Require less skill
Make it easy to move from one exercise to next
Allow easy isolation of muscles and muscle groups
Support back
Have limited availability
Are inappropriate for performing dynamic movements
Allow limited number of exercises
Train muscles rather than movements.
Place minimal stress on core stabilizing muscles (those in torso)
Allow dynamic movements
Allow user to develop control of weights
Allow greater variety of exercises
Are widely available, inexpensive, and convenient for home use
Train core stabilizing muscles
Are better for building power
Are truer to real life situations – strength transfers to daily activities.
Are not as safe
Require spotters
Require more skill
Cause more blisters and calluses.

25. Other training methods and types of equipment
Resistance bands
Elastic strips or tubes of rubber material that are inexpensive, lightweight and portable
Exercise Balls
Extra large inflatable balls
Can be used to work the entire body
Particularly effective working the so- called stability muscles in the abdomen, chest and back muscles.

26. Pilates
Involves the use of specially designed resistance training devices, although some classes feature just mat or floor work.
Focuses on strengthening and stretching the core muscles in the back, abdomen, and buttocks to create a solid base support for whole body movement
Gives emphasis to concentration, control, movement flow and breathing.

27. No-equipment calisthenics
Uses your own body weight as resistance for strength training
Include exercises such as curl ups, push ups, step ups, heel raises, chair dips, and lunges.

28. Applying the FITT principle
Frequency of exercise:
At least two days per week for weight training
1 day of rest between workouts
Split routine: work out upper body one day and lower body the other.
Intensity of exercise:
Choose weights based on your current level of muscular fitness and your fitness goals.
Exercise should be heavy enough to fatigue your muscles but light enough for you to complete the repetitions.
A program should include both higher intensity exercises and lower intensity exercises to develop fast-twitch and slow- twitch muscle fibers.

29. Time of exercise: repetitions and sets
To improve fitness you must do enough repetitions of each exercise to fatigue your muscles
The heavier the weight, the fewer repetitions.
Set refers to a group of repetitions of an exercise followed by a rest period.
Doing more than one set of each exercise increases strength development.
Rest intervals depend on the amount of resistance (1-3 min)
You can save time in your workouts alternating sets of different exercises.

30. Type or mode of exercise:
For overall fitness include exercises for your neck, upper back, shoulders, arms, chest, abdomen, lower back, thighs, buttocks and calves about 8 – 10 exercises in all.
It is important to balance between agonist and antagonist muscle groups
Do exercises for large muscle groups or for more than one joint before you do exercises that use small-muscle groups or single joints.

31. Strength training exercises for major muscle groups (8-10 exercises)
Warm up and cool down
Warm up before every weight training session and cool down afterward
Warm up
5-10 min
Strength training exercises for major muscle groups (8-10 exercises)
Cool – down 5-10 min
Exercise
Muscle group developed
Frequency: at least 2 days a week
Intensity/resistance: weights heavy enough to cause muscle fatigue when exercises are performed with good form for the selected number of repetitions.
Time/repetitions: 8-12 of each exercise. Sets: 1, rest 1-2 minutes between exercises.
Type of activity: 8 – 10 strength training exercises that focus on major muscle groups.
Bench press
Pull-ups
Shoulder press
Upright rowing
Biceps curls
Lateral raises
Squats
Heel raises
Abdominal curls
Spine
Extensions
Side bridges
Chest, shoulders, triceps
Lats, biceps
Shoulders, trapezius, triceps
Deltoids, trapezius
Biceps
Shoulders
Gluteals, quadriceps
Calves
Abdominals
Low and mind back
Spine extensors
Obliques, quadratus, lumborum

32. Getting started and making progress
Learn the exercises first
Choose a weight that you can move easily through 8 – 12 repetitions
1 set for each exercise
Rest 1 – 2 min between exercises
Gradually add weight and sets to your program over the first few weeks.
Apply the two for two rule: When you can perform two additional repetitions with a given weight on two consecutive training sessions increase the load.
Maintain your gains by training 2-3 days per week. Monitor your progress.

33. Weight training safety
Use a proper lifting technique
Use spotters and collars with free weights

34. Weight training safety
Be alert for injuries
Be cautious about the use of supplements and drugs
Most of these substances are ineffective, expensive and may be dangerous
A balanced diet should be your primary nutritional strategy.

35. LAB Lab 8.1 Lab 8.2 Repetition maximum RM
Functional leg strength tests
Curl – up test
Push – up test
Squat endurance test