Physical Education. Becker High School Resource Manual. Forever Fit

Transcription

1 Physical Education Becker High School Resource Manual Forever Fit

2 Chapter 1 Seeing The Total Picture The goal of most individuals is to lead a happy, healthy life. This goal is difficult to achieve when one lacks endurance to perform daily tasks without undue fatigue, the ability to reduce muscular tension and stress, and the flexibility that prevents nagging aches and pains. Achieving this goal requires a dedication to maintain a balance between the health-related fitness components: cardiorespiratory endurance, muscular strength, muscular endurance, flexability and body weight and composition. However, physical fitness is only one part of the total health picture. Emotional, interpersonal, social, and spiritual health also interact to determine the quality of life. Thus, by pursuing an active life-style that incorporates the five health-related fitness components, a person improves his or her overall health and minimizes the risks of disease and disability. TERMS FOR THlS CHAPTER FITNESS: The entire human organism's ability to function efficiently. EXERCISE: Purposeful physical activity. HYPOKINETlC DISEASE: Diseases or disorders associated with lack of physical activity or too little regular exercise. SEDENTARY: Being inactive. Fitness is the reward for leading a physically active life. The American Affiance for Health, Physical Education, Recreation, and Dance (AAHPERD) defines fitness as a physical state of well being that allows people to do the following: 1. Perform daily activity with vigor. 2. Reduce their risks of health problems related to lack of exercise. 3. Establish a fitness base for participation in a variety of physical activities. This indicates that fitness is a relative term that relates to our everyday living. For example, performing tasks such as climbing several flights of stairs, mowing the grass with a push mower, planting a garden, or carrying a heavy suitcase might fatigue an unfit person very quickly, while these tasks are well within the limits of a fit individual. Unfortunately, there is a growing body of evidence that demonstrates that the sedentary life-style is causing major deterioration in normal body functions. Such problems as osteoporosis, hypertension, obesity, and mental health problems (depression, anxiety) and hypokinetic disease are concomitant to physical inactivity.

3 Benefits of Regular Exercise 1. Improved appearance. 2. Improved alertness and improved school performance. 3. Increased efficiency of the heart and lungs. 4. Increased muscular strength and endurance. 5. Improved ability to handle stress. 6. Possible delay in aging process. 7. Maintenance of proper body weight. 8. Improved confidence and self esteem. 9. Few sleep problems. 10. Improved quality of life by minimizing the risk of disease and disability. 11. Early development of good posture. 12. Greater efficiency in perforating motor tasks and sport skills. 13. Establishment of fitness as a lifetime interest. Children learn best by example and from patterns of behavior within the family. Recent studies (Brody, 1990; Corbin, 1987) indicate that parental exercise habits and the time spent with their children in physically active pursuits are the main factors that influence children's participation in physical activity. By making fitness a regular part of life during childhood, the fit child should become and remain a fit adult. REFERENCES Corbin, C.B. (1987). Youth Fitness, Exercise, and Health: There Is Much To Be Done. Research Quarterly for Exercise and Sport, 58, Koplan, J.P., Casperson, C.J., & Powell, K.W. (1989). Physical Activity, Physical Fitness, And Health: Time to Act. Journal of the American Medical Association, 262, Nelms, B.C. (1990) They Need More Exercise. Journal of Pediatric Health Care, 4(4), Ross, J.G., Pate, R.R. (1987). The National Children And Youth Fitness Study II: A Summary of Findings. Journal of Physical Education, Recreation, and Dance, 58 (9), Simons-Morton, B.G., O'Hara, N.M., Simons-Morton, D.G., & Parcel, G.S. (1987).Children And Fitness: A Public Health Perspective. Research Quarterly for Exercise and Sport, 58, Siscovick, D.S., et al. (1985). The Disease Specific Benefits And Risk Of Physical Activity And Exercise. Public Health Reports, 100,180.

4 Cardiovascular Benefits of Regular Exercise The relationship between physical activity and cardiovascular disease was presented in Chapter 5. It was shown that participation in some form of regular exercise may reduce the incidence of disease associated with the heart and circulatory system. It is important to examine some of the actual changes that take place within the body and their relationship to the cardiovascular system. In studying these changes, certain health benefits that can result from regular participation in an exercise program will be discussed, and it will therefore be possible to understand more clearly the mechanisms involved in the relationship between exercise and heart disease. In this chapter the term exercise will be used to refer to regular participation in an exercise program designed specifically for the improvement of the cardiovascular system. Cooper indicates the following, for an exercise program to be beneficial to the cardiovascular system: 1. If must be vigorous enough to produce a sustained heart rate of 150 beats per minute or more. 2. It must be continued at this level for at least five minutes. 3. It must be performed regularly. The type of activity engaged in is therefore unimportant, provided it meets the above requirements. It should be noted, however, that all physical work and exercise does not necessarily result in equally marked changes in the heart. SUMMARY Several of the changes that take place as a result of exercise could explain why there is a reduction in the incidence of cardiovascular disease associated with regular participation in a well-designed exercise program: 1. Increase in the efficient of the heart. 2. Increase in the coronary blood supply. 3. Development of collateral circulation. 4. Reduced resting heart rate, meaning more rest for the heart. 5. Quicker clearance of fat from the bloodstream. 6. Reduction in the clotting ability of the blood. 7. Reduction in excess weight and fat. 8. Reduction in systolic blood pressure. Associated with each of these changes is a possible explanation as to why regular exercise might reduce one's changes of suffering from some form of cardiovascular disease. An understanding of the material presented in this chapter should make it possible for a student to become aware of the relationship between each of these changes and cardiovascular disease. Other changes that relate to the cardiovascular system resulting from regular exercise include the following: 1. An increase in the amount of hemoglobin and total blood volume, which would make it possible for the body to deliver more oxygen to the body. 2. An increase in the efficiency of the lungs, which would allow them to process more air with less effort. 3. An increase in the maximal amount of oxygen that the body is able to utilize.

5 Chapter 2 Strength Training Muscular strength is the ability of a muscle group to exert maximum force against a given resistance. Muscular power is the speed at which muscular force can be generated (example: jumping). Fast-twitch muscle fibers are predominately used for this type of activity. Strength is needed to meet daily challenges, not only for sports performance but for health maintenance. Research has demonstrated that strength training through progressive resistance exercise (PRE) training increases lean muscle tissue and strength of the muscles, bones, ligaments, and tendons. This increased strength d decreases the risk of osteoporosis, poor posture, and low back problems due to weak abdominal and muscle imbalances. (Corbin & Lindsey, 1990) The use of strength training for students has, however, been a matter of controversy. The following information regarding the effectiveness, safety, and health benefits should clear up most of this uncertainty. Perhaps the greatest concern to parents and teachers should be with the method used to gain strength. Weight lifting is a sport in which the participant attempts to life maximum weight in one single effort. Generally, free weights provide the resistance. Weight training is performed with a series of at least three or four consecutive sub maximal repetitions against resistance created by free weights, machines, or the body's own weight. The very nature of weight lifting is more competitive and often promotes an unsafe environment for students. The American Academy of Pediatrics (1983) was cautious in its endorsement of supervised weight training for adolescents, condemned weight lifting competitions for adolescents, and noted that there was no significant improvement in strength or increase in muscle mass for early adolescents and children. However, more recent studies (Sewall & Micheli, 1986; Rains, 1987) indicate that supervised strength programs can be conducted safely, with significant gains in strength with little or no loss in body flexibility. The advantages of strength training appear to outweigh the disadvantages. These benefits include: * Increased bone mineralization may help prevent osteoporosis (Loucks, 1988). * Strengthened abdominal, back, and leg muscles may facilitate proper posture, prevent low back problems and muscle imbalances. * The development of muscle mass increases energy requirements. * Improved muscle tone enhances appearance, self-esteem, and body image. * Reduced chance for sports-related injuries due to joint stability. When planning a strength training program for students,these recommendations should be followed: * Training should be supervised. * Proper posture and technique should be demonstrated. * Maximal lifts should be avoided until 16 or 17 years of age. * Training should involve high repetitions (7-11) at low resistance.

6 The remainder of this chapter will discuss progressive resistance exercise (PRE) training, the three types of muscle contractions, FIT guidelines for strength and endurance, training principles, strength differences for boys and girls, and guidelines. Terms for this Chapter ATROPHY : A decrease in muscle size. CONCENTRIC: A contraction where the muscle shortens. ECCENTRIC: A contraction where the muscle lengthens. EXTENSION: An increase in the angle of a joint. FLEXION: A decrease in the angle of a joint. FREE WEIGHTS: Barbells, dumbbells. HYPERTROPHY: An increase in muscle size. ISOKINETIC: A contraction where speed is held constant and the resistance is varied. ISOMETRIC: A muscle contraction where the muscle remains the same length; there is no observable movement. ISOTONIC: A muscle contraction in which the muscle changes length, either shortening or lengthening, through a full range of motion against a constant resistance. POWER: The speed at which muscular force can be generated. PROGRESSIVE RESISTANCE EXERCISE (PRE): An exercise in which resistance is added gradually. REPETITION (reps): The number of times an exercise is performed. REPETITION MAXIMUM (RM): The maximum amount of resistance one can move a given number of times; 1 RM = maximum weight lifted one time; 6 RM = maximum weight lifted six times. SET: A specified number of repetitions. STRENGTH: The ability of a muscle to exert force with one maximal effort. WEIGHT LIFTING: A sport in which the participant attempts to lift maximum weight in one single effort. WEIGHT TRAINING: Performed with a series of at least 3 or 4 consecutive sub maximal repetitions against resistance.

7 THREE TYPES OF MUSCLE CONTRACTIONS When a muscle contracts it may shorten, lengthen, or remain the same size: CONCENTRIC CONTRACTIONS When a dumbbell is lifted from an extended to a flexed position during the bicep curl exercise, the bicep muscle exerts force and shortens, and the weight is lifted. This shortening phase is a concentric contraction. ECCENTRIC CONTRACTIONS When the dumbbell is lowered from the flexed to the extended position during the bicep curl exercise, the bicep muscle lengthens, and the weight is lowered. The lengthening phase is an eccentric contraction. ISOMETRIC CONTRACTIONS If the dumbbell is momentarily held half way between full flexion and full extension, the muscles are exerting force but there is no observable movement. When there is no change in muscle length, it is isometrically contracting. PRIME MOVERS AND ANTAGONISTS During movement, the muscle that contracts concentrically is termed the prime mover. Muscles that produce the opposite action are called antagonists. For smooth lifting during the bicep curl, the bicep muscle (prime mover) must shorten while the tricep muscle (antagonist) lengthens. During the lowering (eccentric) phase of the exercise, the tricep is the prime mover and the bicep is the antagonist. There are also muscles that perform joint stabilizing and neutralizing functions. They are called stabilizer and neutralizer muscles.

8 STRENGTH DIFFERENCES IN BOYS AND GIRLS Muscle strength is determined by the number and size of muscle fibers involved in a given contraction. Muscle fiber number is determined genetically while fiber size changes as the child matures and gains strength. Boys and girls are equal in strength until puberty (about 12 years). At that time the make hormone, testosterone, increases, thus aiding in the development of bigger and stronger muscles. Most girls have very little testosterone, so their muscles become strong and firm when performing strength training exercises. Generally, girls are weaker than boys in arm and shoulder girdle strength, but equal to boys in leg strength. THREE TYPES OF STRENGTH TRAINING EXERCISES ISOMETRIC EXERCISES: are those in which there is no movement (static). The force is exerted against an immovable object. An example would be pressing against a ball. Isometric exercises are used mainly for rehabilitative purposes or for activities that require static strength. For example, in archery the bow arm must be strong enough to hold the bow away from the body in a steady position for several seconds, By replacing the bow with a dumbbell and holding it in the exact position, static strength will be gained resulting in less fatigue and better stability. Very little equipment is necessary for these exercises. ISOTONIC EXERCISES: are the most commonly used. These exercises result in the muscle shortening and lengthening against a constant resistance. Calisthenics, or exercises using free weights (dumbbells and barbells), or weight machines provide a constant resistance through the full ROM. For example, when performing a push-up, the weight of the body is moved by the muscles in the chest (pectorals) and arms (biceps and triceps). When performing a biceps curl while holding a dumbbell or using latex bands, the biceps muscle is shortening and lengthening. ISOKINETIC EXERCISES: are the best; however, it is impossible to perform them without special machines. These devices keep the speed constant and vary the resistance through the full ROM.

9 STRENGTH AND ENDURANCE TRAINING GUIDELINES AND SAFETY PRECAUTIONS 1. Each workout should be properly supervised and recorded! 2. Proper posture and tfinhnignfi for each exercise should be taught. 3. "Use It or Lose It." If a muscle is not exercised it will become weak and flabby. This is called atrophy. Regular exercises will cause the muscle to increase slightly is size. This is called hypertrophy. 4. Warm-up and stretch thoroughly before training begins. 5. Do not hold vour breath while lifting. Exhale as vou raise or push the weight away and inhale as vou lower it. 6. Raise and lower the weight or body part through a full ROM smoothly and slowly 7. Avoid locking the joints and maintain good posture. 8. Small muscles fatigue very quickly. Begin the workout with the larger muscle groups (legs,back, chest), then exercise the smaller groups (shoulders, arms). Abdominal can be exercised last. 9. Cool down and stretch after lifting. 10. Children diagnosed with chronic cardiovascular conditions like Marfan syndrome or aortic valve disease should avoid strength training exercises. 11. "10-15 PROGRAM" Begin with a weight that can be lifted 10 times. Gradually add one repetition at a time until 15 reps are achieved. Add weight so that reps can be performed. Begin with 1 set of 10 reps. All presses and curls are performed in a lying or sitting position. AVOID all standing lifts and full squats. 12. AVOID overloading one side of the joint and forgetting about the other side. Muscles that work opposite sides of the joint must be of equal strength, otherwise the joint is prone to injury. Focus on strengthening the following weak muscles: STRONG BICEPS QUADRICEPS ERECTOR SPINAE PECTORALS ABDUCTORS GASTROCNUMIUS WEAK TRICEPS HAMSTRINGS ABDOMINAL RHOMBOIDS/TRAPEZIUS ABDUCTORS TIBIALIS ANTERIOR

10 CARDIORESPIRATORY ENDURANCE Cardiorespiratory endurance (cardio=heart and respiratory=lungs) is the ability of the heart, blood vessels, blood, and respiratory system to deliver oxygen to the entire body and to remove waste. This component is often considered the most important because the function ofthese two systems are vital to healthy living. Terms synonymous with cardiorespiratory endurance include cardiorespiratory fitness, cardiovascular fitness and endurance, and aerobic fitness. Individuals possessing endurance and fitness in this area are able to perform prolonged physical activity without undue fatigue. The critical period for enhancing cardiovascular function through exercise training remains controversial. Most researchers agree, however, that positive improvements in cardiovascular endurance, especially in lower fitness level students, occur in response to aerobic training provided the students follow the adult fitness criteria; frequency = three to five days per week, intensity = 60-90% of the predicted maximum heart rate, and time = minutes (Shephard, 1982; Krahenbuhl et.,1985; Sady, 1986; Vaccaro & Mahon, 1987). Experts caution against subjecting the pediatric athlete to serious endurance training programs. Endurance activities may be useful in developing neuromuscular skill, mechanical efficiency, and "psychological toughness," but intense training at this stage could lead to injury and early burnout (Rowland, 1990). One helpful approach is to encourage working at a moderate level of intensity. As the limits of a student's capacity in any of the fitness components is approached, the risk for injury increases. Working at moderate intensities can still produce fitness gains while minimising the injury risk. Most students will stop before injury or excessive discomfort is experienced. However, the competitive pressures produced by coaches, teachers, parents, or peers can push students into danger territories. Students should not be instructed to work through pain! Specialists agree that one to two miles three times per week is a safe distance for well-conditioned children to run without risk of musculoskeletal injury. For running, the American Academy of Pediatrics (1982) recommends that children should not participate in marathon races (26.2) miles) and children under 14 years of age should not train or compete at distances greater than 10K (6.2 miles).

11 HEART DISEASE AND FITNESS Current research indicates that coronary heart disease (CHD) has its origin in childhood. The prevalence of risk factors for active and apparently healthy boys and girls aged seven to 12 years showed obesity, family history, and high blood lipids to be the most frequently occurring risks. These children and especially obese children who already are at risk for CHD are in desperate need for risk intervention programs. School-based programs aimed at educating children on proper nutrition, regular exercise and behavior therapy have proved to reduce these risks. But by far, regular moderately intense exercise has been the more potent intervention that resulted in changes in CHD risk profiles. The recommended activity to achieve cardiorespiratory fitness is AEROBIC activity because the heart is a muscle. When it is exercised continuously at moderate intensity for a prolonged period of time, it becomes stronger and slightly larger. This increase allows greater volumes of oxygen and nutrients to be delivered to the body with each beat. While sustained periods of aerobic activity are recommended in this area, do not forget the use of anaerobic activities when dealing with elementary students. A child's natural inclination for anaerobic activities which require short, intense, and periodic bursts of speed should prove to be helpful. Attempts to understand the causes and this the control of CHD have resulted in many research studies on this topic. Based on the results ofthese studies, several risk factors have been identified as being correlated with CHD. Risk factors are classified as being controllable or uncontrollable. Uncontrollable risk factors include: Age Race Gender Heredity Controllable risk factors are: PRIMARY F ACTORS SECONDARY F ACTORS 1. High Blood Pressure 1. Obesity 2. High Levels of Serum Triglyceride 2. Physical Inactivity 3. High Levels of Serum Cholesterol 3. Stress (Hyperlipidemia) 4. Personality Type 4. Cigarette Smoking

12 THE DIRTY DOZEN: CORONARY HEART DISEASE RISK FACTORS 1. BLOOD LIPID - cholesterol > 170 mg/dl 2. OBESITY-> 20% body fat 3. SMOKING 4. PHYSICAL INACTIVITY 5. HYPERTENSION 6. DIABETES MELLITUS 7. DIET 8. HEREDITY 9. PERSONALITY & BEHAVIOR PATTERNS 10. RACE 11. FAMILY HISTORY 12. LEVELS OF STRESS In this chapter the type and amount of exercise necessary for reducing CHD and improving cardiorespiratory fitness will be outlined. TERMS FOR THIS CHAPTER AEROBIC EXERCISE: Aerobic means "in the presence of oxygen." Aerobic exercise is activity for which the body is able to supply adequate oxygen to sustain performance for long periods of time (e.g. walk, jog, bike, swim, etc.) ANAEROBIC EXERCISE: Anaerobic means "in the absence of oxygen." Anaerobic exercise is performed at an intensity so great that the body's demand for oxygen exceeds its ability to supply it (e.g. sprinting, tennis, strength training). CARDIORESPIRATORY ENDURANCE The ability of the heart, lungs, blood vessels to deliver oxygen to the body and remove waste. HEART RATE (HR): The number of times the heart beats per minute. RESTING HEART RATE (RHR): A measure of heart rate taken fouowing inactivity. Most accurately taken upon waking in the morning, before sitting up. EXERCISE HEART RATE (MHR): A measure of heart rate taken during exercise. MAXIMUM HEART RATE (MHR): The highest number of times the heart can beat per minute. While this varies from individual to individual, a commonly accepted formula is person's age = MHR. TARGET HEART RATE: The recommended number of times the heart should beat each minute during aerobic exercise in order to improve aerobic endurance; beats per minute for children, ages TARGET HEART ZONE (THZ): 60-80% of maximum heart rate.

13 CALCULATING YOUR TARGET HEART RATE (THR) Formulas have been devised to determine the lower and upper limits for the target zones for strengthening the heart and lungs and improving cardiorespiratory fitness. These limits depend on each individual's fitness and level of regular activity. The two primary methods for calculating these limits are the Karvonen Formula and Heart Rate Maximum (HRmax) or Age-Predicted Formula. The HRmax, like the Karvonen formula, used age to predict maximum heart rate. But since the resting heart rate is not considered in the HRmax formula, it is generally not as accurate an estimate as the Karvonen Formula. The advantage of the HRmax is that it is simpler to calculate than Karvonen. The following numbers are necessary for these calculations The generally accepted maximum HR is 220 bpm. This maximum drops approximately one beat each year after birth. For example, a 10-year-old child would have a predicted maximum HR of 210 beats per minute. AGE - Age of the individual. TARGET HEART ZONE % of maximum HR RESTING HEART RATE (RHR) - This is best checked in the morning while still lying in bed. The pulse should be counted for one minute. Children's RHR may range from beats per minute (bpm). HRmax FORMULA (Example for a 10-year-old) 1. Find your maximal HR (MHR) age = MMR 2. Find 60% of your MHR MHR x.60 = (Lower limit of Target Heart Rate) 3. Find80%ofyourMHR MHR x.80 = (Upper limit of Target Heart Rate) (age) - 10 (age) 210 (MHR) 210 (MHR) x.60 x bpm (lower limit) 168 bpm (upper limit) TARGET HEART ZONE: 126 to 168 beats per minute.

14 USING A SIX-SECOND COUNT: To determine the lower limit of 126 bpm for 6 seconds: 126/10 = 12.6 or 13 beats To determine the upper limit of 168 bpm for 6 seconds: 168/10 x 16.8 or 17 beats USING A TEN-SECOND COUNT: To determine the lower limit of 126 bpm or 10 seconds: 126/6-21 beats To determine the upper limit of 168 bpm for 10 seconds: 168/6-28 beats KARVONEN FORMULA (Example for a 10-year-old with a RHR of 80) 1. Find your maximum HR (MHR) age = MHR 2. Find your RHR, subtract RHR from MHR MHR - RHR = MHR reserve 3. Find 60% of your MHR reserve MHR reserve x.60% + RHR = (Lower limit of Target Heart Rate) 4, Find 80% of your MHR reserve MHR reserve x.80% + RHR = (Upper limit of Target Heart Rate) = age 210 = MHR -80 = RHR reserve 130 x = RHR 158 bpm (lower limit) = age 210 = MHR -80 = RHR reserve 130 x = RHR 184 bpm (upper limit) TARGET HEART RATE: 158 to 184 beats per minute TAKE THE TALK TEST: A less formal method for determining aerobic intensity is the TALK TEST. It is based on the premise that, while exercising, the student should always be able to hold a conversation. If the student can only gasp out one or two words at a time, the exercise intensity is too intense and the pace of the activity should be decreased.

15 RECOVERY HEART RATE Purpose: * To determine how to figure resting heart rate and target heart zone. * To study the effects of exercise on heart rate. * To study recovery heart rate. Equipment: * Stopwatches, pencils READ THE INSTRUCTIONS CAREFULLY BEFORE BEGINNING THIS ACTIVITY 1. Lie down for 5 minutes. 2. While lying down, measure your resting heart rate. Resting heart rate 3. Stand - measure your starting pulse. Starting pulse 4. Figure target heart zone at 60%-80% levels. 60% maximum heart rate 80% maximum heart rate 5. Begin stopwatch. 6. Exercise (jog, jump rope, step test) until the 60% heart rate is achieved. 7. Continue to exercise until the 80% target heart rate is achieved. This is your exercise heart rate. 8. Stop watch. Record total exercise time below. Total exercise time 9. Cool down by walking. 10. Check your pulse 1 minute after taking exercise heart rate. Pulse after 1 minute 11. Check your pulse every minute after taking exercise heart rate until your pulse is at the starting pulse number. Pulse after 2 minutes 3 minutes 4 minutes 5 minutes 6 minutes 7 minutes 8 minutes 12. How long did it take to reach the starting pulse number? Length of time for pulse to reach the starting pulse number

16 13 THINGS TO REMEMBER 1. Always warm-up before you exercise. 2. Pace your self!! Begin slowly, gradually increase speed. 3. Remember the F-I-T for AEROBIC ACTIVITY. F = Exercise 3 times each week I = Keep your heart rate between 60-80% MHR T = Exercise continuously for 20 minutes. 4. Do aerobic activity like walking, jogging, biking, swimming, skating, and aerobic dancing to strengthen the heart. 5. Remember the F-I-T for ANAEROBIC ACTIVITY. F = Exercise 3-4 times each week I = Keep your speed near 100% for 10 seconds to 2 minutes T = Repeat your intervals times with rest between 6. Do anaerobic activity like soccer, basketball, tennis, tag games and relay games to strengthen the heart. 7. Keep moving when you check your heart rate. 8. Exercise through the first signs of fatigue, stop if there is pain. 9. Always stretch after you exercise. 10. Wear good athletic shoes and loose fitting clothes. 11. Drink water before, during, and after exercise. 12. Cross train so you don't get bored with playing the same activity. 13. Exercise with your family and friends!!!

17 FIT GUIDELINES FOR AEROBIC ACTIVITY FREQUENCY: Three to six days/week INTENSITY: 60-80% Maximum Heart Rate TIME: minutes within the Target Heart Zone/session AEROBIC ACTIVITY is continuous, large muscle, whole body activity performed for a prolonged period of time. Suggested activities include: WALKING, JOGGING, SWIMMING, BIKING, SKATING, ROPE JUMPING, ROWING and AEROBIC DANCING. There are many reasons why aerobic is preferred over anaerobic activity for cardiovascular fitness. One main reason is that aerobic activity is performed at a lower intensity and therefore is more comfortable and can be sustained longer. This allows greater oxygen utilization within the cells. Anaerobic activity is very intense (>85% to 100% MHR) and uncomfortable, so duration is very short. FREQUENCY: Three to four days/week INTENSITY: Short intervals -100% max. speed (10-30 seconds) Long intervals - 90% - 100% max. speed (1/2-2 minutes) TIME: Short intervals - repeat up to 30x with seconds rest between intervals. Long intervals - repeat up to 15x with 3-15 minute rest between intervals ANAEROBIC ACTIVITY is short, intense and requires periodic bursts of speed. Suggested activities include: All sports but especially tennis, soccer, and volleyball because these sports are more active. Tag games and relays also promote anaerobic fitness. REFERENCES American Alhance for Health, Physical Education, Recreation, and Dance (1988). Phvsical Best Manual. Reston, VA: AAHPERD Bar-Or, O. (1989). Trainabihty Of The Prepubescent Child. The Physician and Sportsmedicine, 17, Corbin, C, & Lindsey, P. (1990). Concepts Of Phvsical Fitness (7th ed.), LA: Brown Krahenbuhl, G.S., Skinner, J.S., & Kohrt, W.M. (1985). Developmental Aspects Of Maximal Aerobic Power in Children. Exercise and Sport Science Reviews, 13, Rowland, T.W. (1990). Exercise and Children's Health. Champaign, IL: Human Kinetics.