Exercise Physiology and Fitness
Chapter 7

 

Exercise Physiology & Fitness

nWhat is exercise physiology?

nWhat is the role of physical activity and exercise in achieving physical fitness and health?

nHow do you use the FITT formula to design a fitness program?

nWhat are the contributors and deterrents to fitness?

Exercise Physiology     

nThe study of the effects of exercise on the body.

nBody’s responses and adaptations to exercises

nSystem to subcellular level

nAcute (short term) to chronic (long term) adaptations

 

nPopulation served

nElite performer

nPeople of all ages and abilities

 

Historical Development

nSpecialized area of study - mid 1960s and 1970s.

nLate 1800s, the use of anthropometry to measure changes in students’ development after training programs.

nMcKenzie: Investigating effects of exercise on various systems of the body and the idea of preventative medicine (early 1900s)

nAfter WWII: increased interest in fitness as a result of youth fitness tests and the results of the physicals of men in the military.

n1970s: APS recognized exercise physiology as a specialized area of physiology.

n1974: ACSM: Guidelines for Graded Exercise Testing and Prescription

n1980s and 1990s: Understanding of the relationship between physical activity and health.

n1996:Surgeon General’s Report Physical Activity & Health

n2000: 1st certification exams for Clinical Exercise Physiologists

 

Areas of Study

nEffects of various exercises on various systems of the body

nRelationship of energy metabolism to performance

nEffectiveness of training programs

nEffects of environmental factors on performance

nIdentification of factors that limit performance

nEffectiveness of various rehabilitation programs

nErgogenic aids and exercise

nHealth and therapeutic effects associated with exercise

nEffects of nutrition on performance

 

Specialization

nCardiac rehabilitation

nAssessment of cardiovascular functioning

nPrevention of cardiovascular disease

nRehabilitation of individuals with the disease

nExercise biochemistry

nEffects of exercise at the cellular level

nExercise epidemiology: Relationship between physical activity and mortality

nPediatric exercise science:Scientific study of the response of the body to exercise during childhood and maturation.

 

Physical Fitness

nAbility of the body’s systems to function efficiently and effectively.

nIndividuals who are “physically fit” have the ability to:

n“carry out daily tasks with vigor and alertness, without undue fatigue, and with ample energy to enjoy leisure-time pursuits and to meet unforeseen emergencies.”

 

Physical Fitness           

Health fitness

nBody composition

nCardiorespiratory endurance

nFlexibility

nMuscular endurance

nMuscular strength

Performance fitness

nAgility

nBalance

nCoordination

nPower

nReaction time

nSpeed

 

Physical Activity and Health

nChronic disease – major threat to health today

nHypokinetic diseases

nDiseases caused by insufficient physical activity, often in conjunction with inappropriate dietary practices.

nCoronary heart disease, hypertension, osteoporosis, non-insulin diabetes, chronic back pain, and obesity

 

Physical Inactivity & Health

nInactivity a risk factor for several diseases

nIndividuals who lead a sedentary lifestyle have increased risk of morbidity and mortality.

nInactive individuals have almost twice the risk of CHD as those who are active

nThe degree of risk is similar to cigarette smoking, hypertension, and obesity.

Dose-response Debate

nWhat kind of activity?

nHow much time spent in activity?

nAt what intensity should it be performed?

nHow often in order to see benefits?

 

Consensus Statement

nThere is an inverse and generally linear relationship for rates of all-cause mortality, total CVD, and CHD incidence and mortality and for the incidence of type 2 diabetes.

nAccumulation of at least 30 minutes of moderate-intensity PA on most days of the week is associated with a significant 20%-30% reduction in all-cause mortality.

nAdditional benefits can be derived from increasing the amount and/or intensity of physial activity.

 

Health Benefits

nEnhanced cardiovascular function

nReduction of many cardiovascular disease risk factors

nIncrease ability to perform tasks of daily living

nReduced risk of muscle and joint injury

nImproved work performance

nImproved physical appearance, self-image, and sound mental health

nReduction of susceptibility to depression and anxiety

 

 

Health Benefits

nManagement of stress

nEnhancement of self-concept and esteem

nSocialization through participation in physical activities

nImproved overall general motor performance

nEnergy

nResistance to fatigue

nMitigate the debilitating effects of old-age or retain a more desirable level of health for a longer period of time

 

Energy Production for PA

nUse of ATP as energy to perform muscular activity. Two ways to produce ATP:

nAnaerobic system

nWithout oxygen

nHigh energy expenditure, short time (6-60 seconds)

nAerobic system

nWith oxygen

nLower rate of energy expenditure, longer period of time (more than 3 minutes)

 

Principles of Fitness Training

nPrinciple of overload

nTo improve, perform exercises that exceed one’s normal level.

nPrinciple of specificity

nDesign program to reflect specific goals.

nAssess individual’s initial fitness level

nEstablish starting point and design realistic program.

nProgression of program

nRevise program as individual’s level of fitness changes.

 

Principles of Fitness Training

nIndividual differences

nConsider individual’s work, diet, & lifestyle in program design.

nWarm-up, workout, cooldown components

nHelps prevent injury and prepares body for exercise as well as returns it to a normal state.

nSafety

nMedical screening & environmental conditions

nBehavioral factors

nMotivation of individual to adhere to fitness program

 

Planning a Fitness Program

nThreshold of training

nMinimal level of exercise needed to achieve desired benefits.

nTarget zone

nDefines the upper limits of training and the optimal level of exercise.

nNeeds and goals of individual

nProgram should meet the goals of the individual

nFITT Formula

 

FITT formula

nFrequency

nNumber of sessions each week

nIntensity

nDegree of effort put forth during exercise.

nTime

nDuration of activity

nType

nMode of exercise being performed

 

Cardiorespiratory Endurance

nBody’s ability to deliver oxygen effectively to the working muscles to perform physical activity.

nMost important component of health fitness.

nHelps prevent hypokinetic disease.

nConcerned with the aerobic efficiency of the body.

 

Cardiorespiratory Endurance

nFrequency:     3 to 5 times per week

nIntensity:        55% to 90% HRMAX

nTime:             20 - 30 minutes

nType:             Aerobic activities

Target Zone     

nHRMAX= 220 bpm - age

nTarget zone = 55% to 90% HRMAX

nLower threshold target HR= HRMAX x 55%

nUpper threshold target HR= HRMAX x 90%

 

Body Composition       

nPercentage of body weight composed of fat as compared with fat-free or lean tissue.

nObesity is associated with numerous health problems and earlier mortality.

nObesity in America

            http://www.cdc.gov/nccdphp/dnpa/obesity/trend/maps/obesity_trends_2005.ppt

nDetermination of the cause of obesity is important.

 

Body Composition

nBody composition is influenced by nutrition and physical activity.

nEnergy balance is important to achieving a favorable body composition.

nEnergy expenditure through:

nbasal metabolism (maintenance of essential life functions)

nwork (including exercise)

nexcretion of body wastes

 

Body Composition

Body Mass Index

nEstimated –

nWeight in pounds X 703 divided by height in inches squared

nOften used in large scale surveys because of ease of collecting large amounts of data

 

Energy Balance

nNumber of calories taken into the body as food minus number of calories expended

nCaloric expenditure

nNeutral balance

nCaloric intake equals expenditure.

nPositive balance

nMore calories consumed than expended.

nNegative balance

nMore calories are expended than consumed.

 

Body Composition Improvement

nDecreasing percentage of fat

nDecrease caloric intake through diet.

nIncrease caloric expenditure through physical activity and exercise.

nModerate decrease in caloric intake and moderate increase in caloric expenditure.

nFollow sound practices

nObsession with weight loss, in conjunction with many other factors, may contribute to the development of an eating disorder.

 

Measurement of Body Composition

nHydrostatic weighing

nSkinfold measurements

nSkinfold caliper from selected sites

nUse of formulas to calculate percentage

of body fat

nBody mass index (BMI)

nheight-to-weight ratio

 

Muscular Strength & Endurance

nMuscular strength is the ability of a muscle or a muscle group to exert a single force against a resistance.

nMuscular endurance is the ability of a muscle or muscle group to exert force repeatedly or over a period of time.

nMaintenance of proper posture; protect joints.

nProduction of power to enhance performance.

nUse it of lose it!

 

Exercises

nIsometric exercises

nMuscle exerts force against an immovable object.

nStatic contraction

nIsotonic exercises

nForce is generated while the muscle is changing in length.

nConcentric and Eccentric contractions

nIsokinetic exercises

nContractions are performed at a constant velocity

 

Development of Muscular Strength and Endurance

nPrinciple of Overload is critical.

nRepetition - performance of a movement through the full range of motion.

nSet - number of repetitions performed without rest.

nStrength

nLow number of repetitions with a heavy resistance.

nEndurance

nHigh number of repetitions with a low resistance

 

Flexibility

nMaximum range of motion possible at a joint

nJoint specific: better range of motion in some joints than in others.

nCan prevent muscle injuries & low-back pain

nDecreased flexibility can be caused by:

nSedentary lifestyle (lack of use of muscles)

nAge

nHigh amounts of body fat

nStress

 

Improvement of Flexibility

nBallistic stretching

nMomentum generated from repeated bouncing to stretch. (Not recommended)

nStatic stretching

nSlowly moving into a stretching position and holding for a certain period of time (10-30 seconds; 5 times).

nContract-relax technique

nRelaxing of the muscle to be stretched by contracting the opposite muscle (hamstrings/quadriceps)

nMeasurement of flexibility-goniometer

 

Conducting Fitness Programs

nProvide for cognitive and affective goals as well as physical activity.

nMake fitness enjoyable.

nEstablish goals and a plan of action to attain them.

nMonitor progress.

nProvide for maintenance of fitness.

nFitness requires personal commitment.

 

Effects of Training

nLower oxygen consumption

nLower pulse rate

nLarger stroke volume

nLower rise in blood pressure

nSlower respiration rate

nLower rate of lactic acid formation

nFaster return to “normal”

 

Effects of Training

nGreater cardiorespiratory efficiency.

nGreater endurance.

nMore “work” can be performed at less cost.

nImprovement in fitness components.

nCoordination and timing of movements are better.

 

Physical Activity & Health

nAdults - 30 minutes of physical activity equal to brisk walking on most, preferably all, days of the week.

nChildren – 60 minutes of physical activity on most, preferably all, days of the week

nActivity of greater intensity will yield greater health benefits.

nStrength-developing activities at least twice a week.

nPhysical activity as an integral part of one’s lifestyle.

Environmental Considerations

nHot and humid weather

nUse extreme caution

nHeat cramps, heat exhaustion, heat stroke

nFluid replacement

nAdaptation

nExtreme cold weather

nHeat conservation

nHypothermia

nFrostbite

 

Nutrition and Fitness

nNutrients

ncarbohydrates

nfats

nproteins

nvitamins

nminerals

nwater

nMaintaining water balance is important.

nA well-balanced diet is necessary to obtain all the nutrients required by the body.

 

Nutrition

nFood pyramid offers guidelines for eating a balanced diet.

nCurrent U.S. diet is too high in fat, cholesterol, sugar, and sodium and lacking in carbohydrates and fiber.

nCarefully monitor caloric intake AND caloric expenditure.

nSpecial diets for special situations.

Dietary Guidelines – Aim, Build, Choose for Good Health

nAim For Fitness

nAim for a healthy weight.

nBe physically active each day.

nBuild A Healthy Base

nLet the Pyramid guide your food choices.

nEat a variety of grains, fruits, and vegetables daily.

nKeep food safe to eat.

nChoose Sensibly

nChoose a diet low in saturated fat, cholesterol, and moderate in total fat.

nChoose beverages and foods to moderate intake of sugars.

nChoose and prepare foods with less salt.

nDrink alcoholic beverages in moderation.

 

Ergogenic Aids

nWork-producing substances or phenomena believed to increase performance

nUsed to enhance energy use, production, and/or recovery in quest for improved performance

nForms

nMechanical

nPsychological

nPharmacological

nPhysiological

nNutritional

 

Caffeine

nStimulant, restricted by IOC – standard up to 6 to 8 cups of coffee

nEnhances muscle tension development, increased alertness, decreased perception of fatigue, increased endurance performance

nEffect depends on dosage and amount of caffeine athlete typically consumes

nSide effects – very rapid heart rate, diuresis, insomnia, nervousness, diarrhea, anxiety

 

Carbohydrate Loading

nUsed in endurance events lasting 60 to 90 minutes or longer in order to maintain pace and delay fatigue

nChange training regimen and modify diet to eat more complex carbohydrates than normal in order to store additional glycogen in muscles and liver to provide extra energy

nPre-event meal – 1 to 5 grams of carbohydrate per kilogram of body weight 1 to 4 hours prior to event

 

Hydration and Sports Drinks

nProper hydration is important for safety reasons and to improve performance.

nFluid replacement during exercise is associated with lower heart rate, body core temperature, and levels of perceived exertion.

nWater – 4-6 ounces for every 15-20 minutes of exercise

nSports drinks – add fluid as well as replace lost electrolytes and supply additional carbohydrates

 

Creatine

nUsed in an effort to increase stores of muscle phosophocreatine and have more fuel available to support short, high intensity activity

nUsed in conjunction with a resistance training program to maximize muscle strength and increase fat-free mass

nACSM – creatine supplementation enhances exercise performance in events involving short periods of extremely powerful activity, especially during repeated efforts.

Anabolic-Androgenic Steroids

nSynthetic forms of male hormone testosterone – testosterone secreted by testes is responsible for the development of masculine characteristics and promotion of growth of tissue, muscle mass, weight, and bone growth

nTaken orally or injected in 10 to 100 times the recommended therapeutic dosage

nBanned by IOC and some sport organizations

nSerious side effects, some irreversible, associated with chronic use including increased risk of heart disease, liver tumors, cancer, hypertension, mood swings, aggressive behavior.