Intro To Exercise Science Module 2

Cardiovascular endurance

Your body’s ability to delivered oxygen to working muscles during exercise (pacer t3st, V02 max assessment, YMCA step up test)

Muscular endurance

Your muscles ability to exert force repeatedly or for an extended period of time ( # of push ups you can do, flexed arm hang,planks till failure, partial curl up)

Muscular strength

Your muscles ability to exert a maximum amount of force in one effort (one rep max, isometric manual muscle assessments, grip strength assessment)

Flexibility

Your muscles and joints ability to move through their full range of motion (sit n reach test, shoulder mobility screen)

Body composition

Body’s ratio of lean muscle to stored fat (DEXA machine, body pod, hydrostatic weighing, skin fold, BMI calculator)

Overweight

Body weight that exceeds some predetermined average for height

Usually experienced an increase in fat but not always, as in the case of muscular atheletes

Overfat

Condition of having more than a healthy amount of body fat

Obesity

Over-fat condition that is accompanied by a host of comorbidities

Comorbidities of obesity

• glucose intolerance/insulin resistence

• Dyslipidemia

• Type 2 diabetes

• Hypertension

• Increased visceral fat tissue

• Increased risk of coronary heart disease and certain cancers

Obesity Rates

Adult prevalence rate: about 41.9%

Childhood prevalence rate: about 19.7%

Women more likely to be obese at all ages

Differences in prevalence by racial/ethnic groups

Reason of increase in obesity

Increasingly convenient lifestyle, characterized by environments that promote unhealthy food intake and physical inactivity

Main risk of obesity

Having too much body fat

It’s important to be able to distinguish between fat and fat free mass

Criterion measures of body fat

Hydrostatic weighing/underwater weighing

Air displacement plethysmography (bodpod)

Dual energy x ray absorptiometry (DEXA)

Hydrostatic/underwster weighing

estimates body composition using measures of body weight, body volume, and residual lung volume

Air Displacement Plethysmography (BodPod)

• similar concept to hydrostatic weighing Air displacement

• Estimates body composition using measures of body weight, body volume, and sometimes residual lung volume

• Replacing hydrostatic weighing as standard in labs

Dual Energy X-RY Absorptiometry (DEXA)

Measures absorbance of x-rays at two different energies

Field Methods of Body composition assessment

• body mass index (BMI)

• Waist circumference

• Waist to hip ratio

• Skinfold measures

• Bio electrical impedance analysis (BIA)

Body mass index (BMI)

Predictor of CVD, type 2 diabetes

• risk factor greater than or equal to 30

• BMI is calculated as the ratio of one’s weight to height

BMI = weight (in kg) / height (in meters squared)

Waist circumference

Predicts obesity related health risks

• risk factor: men greater than 102 cm (40 inches), women greater than 88 cm (35 inches)

BMI Calculation Classification

• Underweight: <18.5

• Normal Weight: 18.5-24.9

• Overweight: 25.0-29.9

• Obesity

  • Class 1: 30.0-34.9

  • Class 2: 35-39.9

  • Class 3: greater than or equal to 40

Waist to Hip Ratio

CVD and metabolic diseases of central adiposity

• different values for males and females

• Android vs gynoid shape

Skinfold Method

• indirect measure of subcutaneous adipose tissue

• Skinfold predictions estimate body density (subsequently %BF is estimated from density)

3 site Skinfold measures for male

• chest

• Abdomen

• Thighs

3 site Skinfold measures for females

• triceps

• Suprailium

• Thigh

Suprailia

Diagonal fold in lime with angle of iliac crest

Triceps

Vertical fold, halfway between acromion and olecranon processes

Thigh

Vertical fold, halfway between proximal border of patella and inguinal fold

Chest

Diagonal fold, midway between anterior and axillary line and nipple

Abdomen

Vertical fold, 2cm to right of umbillicus

Bio electrical impedance

Opposition to the flow of a low level electrical current is measured

• adipose increases resistance to current

• Total body water decreases resistance to current

• Increased total body water = increased lean body mass

Heart Rate

Number of times/minute that the heart contracts

Increase in workload/demand = increase in heart rate

Units: beats per minute

Heart Beat

Each cycle of filling and emptying of chambers

Resting Heart Rate

Fluctuates (stress, time of day, eating)

Lower in supine position than sitting or standing

Often, but not always, indicative of cardio respiratory fitness

Classification of Resting Heart Rate

• <60 bpm = bradycardia

• 60 to 100 bpm = normal

• > 100 bpm = tachycardia

Locations for Heart Rate Measurement

Auscultation

• 3rd intercostal space, left of sternum

Palpation

• radial artery

• Brachial artery

• Carotid artery

• Temporal artery

Heart Rate Palpation Technique

• use tips of index and middle fingers

• Apply light pressure

• Start stopwatch simultaneously with pulse beat; 1st beat is zero

• Duration

  • rest: 30 to 60 sec

  • Exercise: 10 sec

Blood Pressure

Pressure exerted on the circulatory system by flow of blood through system

Typically presented as two numbers: systolic and diastolic blood pressure

Presented in units of mm of mercury (Hg)

Systolic Blood Pressure

Pressure of blood in the system when the ventricles are contracting

Diastolic Blood Pressure

Pressure of blood in the system when the ventricles are relaxed and filling

Hypertension

Major CHD risk factor

Primary: essential or idiopathic HTN

Secondary:

• renal

• Endocrine

• Other (pregnancy, drugs)

Diseases Attributed to Hypertension

Heart Failure

Stroke

Cerebral hemorrhage

Chronic kidney

Hypertensive encephalopathy

Retinopathy

Peripheral vascular disease

Aortic aneurysm

Left ventricular hypertrophy

Myocardial infarction

Coronary heart disease

Coronary circulation

Coronary circulation is the function blood supply to the heart muscle itself

Atherosclerosis

Narrowing of blood vessels due to plaque build ups

Hypertension- Number to know

Normal: Systolic BP <120, diastolic <80

Elevated : systolic BP 120-129, diastolic <80

Stage 1 Hypertension: systolic BP 130-139, Diastolic 80-89

Stage 2 Hypertension: Systolic BP greater than or equal 140, diastolic BP greater than or equal to 90

Hypertension Prevalence

15% to 40% of global population

Higher prevalence for Europeans and north Americans than for African Asian and Mediterranean adults

Substantially higher in blacks than other ethnicities/races in the United States

Physical Activity and Hypertension Risk

Inverse relationship between resting BP and levels of Physical activity

Physical activity moderately reduces resting BP (5-7 mmHg)

Even modest reduction in BP reduces CHD risk

Hypertension Risk and aging

Men and women free of hypertension at 55 years of age indicate that the remaining lifetime risks for development of hypertension through 80 years are 93% and 91% respectively

More than 90% of individuals who are free of hyper at 55 years of age will develop it during their remaining lifespan

Hypertension Phenomenon

White coat hypertension

• hypertensions caused by nervousness (not true hypertension)

Masked hypertension

• hypertension that is not typically present when BP is measured

Cuff hypertension

• inaccurate BP readings due to wrong cuff size

• Cuff to small: BP incorrectly high

• Cuff to large: BP incorrectly low

Hypertension Lifestyle Modification

• aerobic exercise greater than or equal to 150 min a week

• Lose weight

• Diet rich in fruit and veggies; low in fat and cholesterol

• Reduce sodium intake

• Limit alcohol consumption

Measuring blood pressure

• place the cuff around the upper arm

• Inflate to pressure above the systolic BP (SBp)

• If SBP is know, inflate cuff approx 20 mmHg above expected value, if SBP is unknown, inflate cuff to approx 160 mmHG

• Place stethoscope over brachial artery in the antecubital fossa and listen

• Should be no sound initially; pressure in cuff is high enough to prevent blood flow

• Gradually (appro 2 mmHG/second) open valve regulating air pressure in cuff

• As prsssure in cuff drops it gets closer to SBP value

• A series of steps follow, known as Korotkoff sound, 5 korotkoff sounds

Korotkoff Sounds

Phase 1: faint tapping sounds which gradually increase in intensity and become at least two consecutive beats (this is the systolic blood pressure)

Phase 2: sounds soften and acquire a swishing quality

Phase 3: the return of sharper sounds

Phase 4: the distinct abrupt muffling of sounds, which becomes soft

Phase 5: the point at which all sounds finally disappear completely ( this is diastolic blood pressure)

Korotkoff Sounds Cont

1st phase defined SBP

2nd and 3rd phases not clinically useful

4th phase: traditional determination of DBP (faint sounds of heartbeat)

5th Phase:more commonly used determination of DBP (easier to define the absence of sound as compared to a quieter sound)

Measurement of BP

• can seem tricky at first (especially how fast to open the air valve to the cuff)

• Gets easier the more times you do it

• Many more opportunities as you progress through EXS courses

• Skill that you should master in conducting on your patient/athelete/client both at rest and during exercise