1. Developing Flexibility and Muscular Fitness

2. At one time physical fitness programs consisted almost entirely of strength and flexibility exercises.
Today, as the emphasis on balanced fitness grows, muscular strength, muscular endurance, and flexibility are assuming new importance.
They can enhance the ability to perform daily tasks and athletic performance.
Muscular fitness makes it easier to perform routine activities such as carrying groceries upstairs, lifting a child, and moving the couch. It is perhaps the most important fitness component for older adults because muscular fitness is essential for carrying out activities of daily living that help maintain functional independence.
Flexibility enables us to reach, bend, twist, and perform movements without excessive tightness or stiffness.
Enhanced muscular fitness allows us to perform vigorous activities with less risk of straining muscles or connective tissue, and so it is important in the prevention and rehabilitation of injuries.

3. FLEXIBILITY
The ability to move the joints through their full range is an asset that can be maintained throughout life.
As children, we are naturally flexible, but as we age, flexibility tends to decrease.
Disuse, injury, excessive body fat, and muscle imbalances are common factors in this loss of range of motion.
You can maintain youthful flexibility by incorporating stretching into your regular workouts.
The flexibility exercises in this section are grouped as follows: a basic fitness flexibility program with exercises for joggers, walkers, aerobic dancers, cyclists, swimmers, and water exercisers and examples of PNF partner-assisted stretches.

4. Benefits and Cautions
Six main benefits can be gained from flexibility development:
• may decrease the risk of injury. When tight muscles restrict the natural range of motion of a joint, the slightest unusual twist can cause a strain or pull, such as a strained hamstring. Inflexibility also is a precipitating factor in overuse injuries such as tendinitis, because inelastic muscles transfer excessive stress to even less pliable connective tissue.
• counteracts age-related declines in flexibility.
• It decreases aches and pains. Tight, inflexible muscles pull unevenly across joints, causing skeletal misalignment, poor posture, unnecessary fatigue, and muscle and joint pain. Stretching can alleviate these problems.
• It increases the ability to move freely and easily and to perform activities such as bending down to tie your shoes, scratching your back, and turning to look back as you are driving.
• It enhances athletic performance. In racquetball, golf, tennis, volleyball, and swimming, greater range of motion and ability to apply force through that range of motion can confer a winning edge.
• It feels good. Stretching reduces muscular tension, promoting relaxation.

5. Types of Flexibility
There are two basic types of flexibility: static and dynamic.
Static flexibility refers to the range of motion that can be achieved through a slow, controlled stretch. Static stretching techniques are those in which you slowly stretch a muscle to the point of tension and hold, such as in holding a sitting hamstring stretch. The stretching force is provided by gravity or the force of one limb pulling on another. When a muscle is stretched and held at a constant length, after a period of time there is a gradual loss of tension and muscle lengthening
Dynamic flexibility is the range of motion achieved by quickly moving a limb to its limits. Dynamic stretching programs employ swinging or ballistic moves such as a high forward kick.
While both types of stretching can increase flexibility, static stretching is preferred in health-related fitness programs because it is highly effective and carries little risk of muscle or joint strain.

6. Principles of Flexibility Development
Both types of flexibility are specific to the joint; that is, flexibility in one leg does not guarantee identical flexibility in the other leg, and flexibility in the shoulders does not ensure flexibility in the lower back.
An individual's flexibility range for a particular joint is not only specific but also partially genetically determined.
Flexibility is determined by joint structure and elasticity of muscle and connective tissue.
While you may not be able to change your genetics, you can improve your flexibility within your genetically determined range of motion.
Flexibility exercises are only part of a balanced fitness program. The goal is to develop and maintain an adequate range of joint motion for ease of movement in your daily activities.

7. Flexibility gains are proportional to the overload applied: to the frequency, intensity, and time (duration) of stretching.
• Frequency: Stretch at least 2 to 3 days a week, daily if possible. Greater flexibility is produced by more frequent stretching.
• Intensity: Low-intensity stretching is best. Progress at your speed.
Stretching is not competitive.
Flexibility changes from day to day, and on some days you might not be able to stretch as far as you did the day before.
Stretch slightly beyond the normal range of motion, to the point of tension, and hold. Do not force a stretch.

8. Time: The ACSM recommends a 10- to 30-second stretch, though holding up to 60 seconds in a cool-down stretch can increase flexibility retention.
• Repetitions: At least four 10- to 30-second sustained stretches for each muscle group are recommended.

9. Guidelines for Flexibility Development
Everyone can benefit from flexibility. To maximize the results from the time invested, implement the following guidelines in your next stretching session:
• Warm up before stretching.
• After warm-up, use stretching as preparation for activity.
While some feel that stretching during warm-up decreases the risk of injury in the activity that follows, there is no evidence that this is true.
Warm-up stretching is different from a planned program of stretching for general flexibility. Warm-up stretching can be limited to what is essential, avoiding overstretching. Stretch the muscle groups used in the activity, hold at the point of tension for 10 seconds, and do not push for flexibility increases. Any gains will be minimal due to the tightening effect of the workout that follows.

10. Guidelines for Flexibility Development
• Stretch for flexibility during cool-down. Muscles are warmest and most elastic at this point. Stretching is easier. More permanent changes in musclelengthening occur with low-force, long-duration stretching if muscles are allowed to cool in a stretched position. Cooling muscles before releasing tension apparently causes muscle collagen (connective tissue), like stretched taffy, to stabilize toward its new stretched length.
• Stop at the point of tension, not pain. Stretching to the point of pain, or until muscles quiver, can risk overstretching injury.
• Stretch slowly and evenly, hold 10 to 30 seconds and release slowly.
• Don't bounce. A slow sustained stretch is more effective.
• Incorporate 8 to 12 stretches into your program.

11. Guidelines for Flexibility Development
Pay particular attention to body areas that are least flexible and stretch them more often.
• Strive for muscle balance. When stretching muscle on one side of a joint, stretch those on the other side as well; for example, if you stretch hamstrings, stretch quadriceps too.

12. Flexibility exercises

13. Other Programs for Enhancing Flexibility
Tai chi and yoga are very old yet newly popular activities that can enhance flexibility and balance as well as reduce stress.

14. Resistance Training: Benefits and Cautions
Resistance training can offer additional benefits whether your goal is health-related fitness or improved athletic performance
Muscle is active, high-metabolic tissue, while fat is storage tissue. Resistance training increases muscle mass, which increases the rate at which you burn calories 24 hours a day, not just during the workout. This makes weight control easier

15. Injury Prevention
Aerobic exercises such as jogging and aerobic dance have the potential to cause injury through repetitive, forceful impact against unyielding surfaces
Strong, flexible muscles and connective tissue can better withstand the stress of many forceful landings during a workout. When ligaments, tendons, muscle, and bone are strengthened through muscular exercise, the risk of injury is decreased.

16. Psychological Benefits
While many people begin an exercise program to improve appearance, many other less visible but equally important effects may result. Benefits in the emotional dimension of wellness from regular exercise include feeling better, decreased stress, decreased depression, and enhanced self-esteem and self-confidence.

17. Social Benefits
In addition to offering physical and psychological benefits, lifting with a partner or friend offers social benefits.
There are many more opportunities for conversation and interaction when you work out with someone than when you watch a movie.
Benefits at Any Age Regardless of your age, you can benefit from resistance training. It is untrue that loss of strength is inevitable with age or that older people cannot gain strength.
While the typical sedentary individual can lose up to 30 percent of his or her muscle mass between the ages of 20 and 70, this loss is more from atrophy due to disuse rather than from aging alone.
Adequate levels of muscular strength are particularly important to older adults to maintain their functional independence and quality of life.
Several studies including people in their 70s, 80s, and 90s participating in resistance training have shown that they increased muscle mass, more than doubled their strength, and improved their functional mobility and ability to perform daily living activities.

18. Disadvantages and Cautions
Although resistance training has many benefits, it does have disadvantages.
Resistance training is not a complete exercise program because it does not develop cardiorespiratory endurance.
As in any physical activity, injury is possible if you are careless or ignore safety procedures. You may have trouble accessing equipment.
Also, you can expect some mild muscle soreness during the first week of the program.

19. Muscle Function
Muscles are made of individual muscle fibers bound together and sheathed in connective tissue. They end in a tendon that connects the muscle to a bone.
Resistance training increases the size and strength of both fiber types as well as their ability to exert force. Muscles cannot expand and push.
Movement is produced as muscle contracts, shortens, and pulls on bones across a joint.
As a muscle on one side of a bone contracts, muscles on the other side must relax to allow movement to occur. The contracting muscle that initiates movement is called the agonist.
Biceps curl demonstrating muscle function.

20. Muscle Fiber Recruitment
When a muscle contracts, only the number of muscle fibers required for that momentary effort will shorten.
Individual muscle fibers cannot contract partially. They are working as hard as possible or not at all. This is called the all-or-nothing principle.
On each subsequent contraction, more fibers must be recruited to continue to lift the same weight. After several muscle contractions, enough fibers are fatigued that the muscle temporarily can no longer generate the same effort in what is called temporary muscular failure.
Muscle fibers increase strength only if they are stimulated by intensity of effort.
If your goal is to develop maximal muscular strength, try to recruit, or activate, as many muscle fibers as possible by working a muscle to a state of temporary muscular failure.
If you are working for health-related fitness levels, a less intense effort is adequate.

21. Muscle Atrophy and Hypertrophy
Muscles adapt to the load placed on them. When the load increases over time, muscular strength and endurance improve. When muscles are not used, they grow weaker, stiffen, and atrophy, or shrink in size.
A dramatic example of muscle atrophy occurs when a person has an injured limb in a cast for several weeks. When the cast is removed, the muscles of the affected limb are noticeably smaller. Increasing amounts of exercise over time are necessary to rebuild muscle strength, size, and flexibility.
When muscles are stimulated by an increased workload, they grow stronger and muscle fibers experience hypertrophy, or increase in size.
This increase occurs in both men and women and is proportional to muscle mass. The average man has about twice the muscle mass of the average woman, and so hypertrophy in men is more pronounced.

22. Gender Differences
Some women worry that they will develop big shoulders or massive, masculine musculature because of weight training.
This myth is reinforced by televised images of women's body-building competitions.
Be assured that shoulder width, like hip width, is influenced by genetics and that significant muscle gains require hours of strenuous weight lifting for many months.
Men have a greater potential for muscle hypertrophy than women do because men have higher levels of sex hormones such as androgen and testosterone, which promote muscle growth.
Some of the strongest women athletes are gymnasts, who have very feminine physiques.
Weight training is also popular with TV and movie stars who exercise to maintain a fit, toned appearance and help control weight. Be assured that massive muscles don't occur by accident or with a 20- to 30-minute muscle-toning workout twice a week.

23. Types of Resistance Training Programs
Two basic types of muscular exercise are static (isometric) and dynamic (isotonic). Different resistance programs have been developed for each type.

24. Static (Isometric) Exercise
Static (isometric) exercise is exercise in which the muscle contracts but does not change length and little or no movement occurs
However, these exercises are not widely used because resistance is applied at only one point in your range of motion, and thus strength development is limited.
Also, it is difficult to know how much force is being exerted, and so strength gains are not as easy to observe as they are when equipment is being used.
However, static exercises can be useful in strengthening muscles after an injury, when dynamic movement would be painful or even increase injury.

25. Dynamic (Isotonic) Exercise
Dynamic (isotonic) exercise is exercise in which the muscle contracts and shortens and movement occurs.
Most daily activities, such as pushing, pulling, and lifting, are dynamic.
Dynamic exercise programs can be done with free weights, exercise machines, elastic resistance, or calisthenics such as crunches and push-ups. Advantages of dynamic exercise are that it strengthens through a full range of motion, the load is measurable, and a variety of isotonic programs are available.

26. Dynamic exercise involves two types of muscle contractions: concentric and eccentric
In a concentric contraction, a muscle shortens as it overcomes resistance. For example, a weight is lifted as the biceps contract during the lifting phase of a biceps curl.
Eccentric contraction occurs when a muscle lengthens and contracts at the same time, gradually allowing a force to overcome muscular resistance; for example, the biceps contract eccentrically during the lowering phase of a biceps curl.
Eccentric contraction is a beneficial component of strength development because it makes up half of the muscular effort.
The same muscles are involved in eccentric and concentric contractions, and so lowering should be done in a smooth, controlled manner for maximal benefit and to prevent potential injury from dropping the weight

27. Principles of Resistance Training
Strength gains are proportional to the load applied and the frequency and intensity of effort. Basic principles of resistance training include progressive overload, specificity, and recovery.

28. Progressive Overload
Progressive overload is the most important principle of resistance training.
To stimulate a muscle to increase strength or endurance, it must gradually be overloaded or forced to work at a higher than normal effort.
Either the number of lifts (repetitions) performed or the amount of weight (load or resistance) must gradually be increased or recovery time between exercises must be decreased. Increasing the number of repetitions or decreasing rest increases muscular endurance. Increasing the weight lifted increases strength.
General programs increase load and repetitions until a desired maintenance goal is reached. You must exercise two to three times a week to improve muscular fitness. Significant strength gains require at least 8 consecutive weeks of training.
To maintain strength, one intense workout is adequate for health fitness. Athletes will need to train at least twice a week to maintain fitness in the off-season.

29. Specificity
The speed of contraction, range of motion, amount and type of resistance, and number and type of exercise are a few of the variables that determine the results of strength training.
If you desire a specific result, such as an increase in muscle mass, your program must be designed and executed to produce that result.

30. Recovery
Exercise stimulates a muscle to take in more protein and nutrients and undergo changes that increase its ability to contract forcefully.
After a workout, you will be weaker, not stronger, due to fatigue. Improvement occurs during recovery, which gives the muscle fibers time to repair and grow.
This requires more recovery time than for the cardiorespiratory system. Strength workouts are best done with 2 to 3 days of rest between sessions to allow recovery and improvement to occur.
Lifting may be done more frequently, using a split routine with the upper body one day and the lower body the next

31. Guidelines for Resistance Training Programs

32. Safety Guidelines for Resistance Training

33. Major muscles of the body.

34. Basic Resistance Training Programs
There are many types of resistance-training programs. The type of program you select will depend on your goals and the type of equipment (if any) you plan to use

35. Free weight exercises

36. There are many ways to develop muscular strength and endurance
There are many ways to develop muscular strength and endurance. While weight training is an excellent program, it is not always convenient.
The abdominal and core strengthening, hip and thigh, and upper-body programs require no special equipment. Partner exercises add a social dimension to a workout.
Elastic resistance produces results without bulky equipment and is easy to take with you for exercise on a trip.
While weights add intensity to a workout, they are not always necessary when the goal is to shape and tone.
Muscles develop firmness by working against a resistance, and that resistance can be your body weight.
These programs emphasize muscular endurance rather than strength by increasing time in contraction or reps. .

39. Elastic resistance exercises.