HNES 472 Ch 3

Health-related physical fitness

Physical fitness components strongly related to overall health and lower chronic disease risk

Main purposes of fitness testing

Collect baseline data develop individualized exercise programs evaluate progress and motivate health goals

Reliable fitness test

A test that produces consistent results

Valid fitness test

A test that accurately measures what it is intended to measure

Ideal fitness test characteristic

Relatively inexpensive

Resting measurements

Heart rate blood pressure height weight and body composition

Testing room temperature

68–72°F or 20–22°C

Testing room humidity

Less than 60%

Resting measurements should be obtained

Before exertional fitness tests

Test environment

Should be quiet private and controlled as much as possible

Comprehensive fitness assessment

Includes screening resting measurements body composition CRF muscular fitness and flexibility

Fitness testing results

Used to develop individualized exercise prescriptions and monitor progress

Risk versus benefit

Should be considered before performing fitness testing

Resting HR stabilization

Rest quietly for at least 5 minutes preferably up to 15 minutes before measuring HR and BP

Pulse palpation site

Radial artery on the thumb side of the wrist

30-second pulse count

Multiply the count by 2 to get beats per minute

Resting BP position

Seated quietly with back supported feet on floor and arms supported at heart level

Before BP measurement

Avoid smoking and caffeine for at least 30 minutes

BP cuff position

Upper arm at heart level with cuff aligned with brachial artery

BP cuff bladder

Should encircle at least 80% of the upper arm

BP inflation

Inflate quickly to 20 mm Hg above the first Korotkoff sound

BP deflation rate

2–3 mm Hg per second

SBP

Korotkoff phase 1 when the first sound is heard

DBP

Korotkoff phase 5 when Korotkoff sounds disappear

BP measurements

Take at least 2 measurements at least 1 minute apart and average them

First BP examination

Measure BP in both arms

Common BP measurement errors

Improper cuff size faulty equipment incorrect stethoscope placement cuff not at heart level and background noise

Central body fat

Body fat concentrated around the abdomen

Central obesity risk

Associated with hypertension metabolic syndrome T2DM dyslipidemia CVD cancer and premature death

Sarcopenia

Degenerative loss of muscle mass and strength associated with aging and reduced physical activity

BMI

Body weight in kilograms divided by height in meters squared

Underweight BMI

Less than 18.5 kg/m²

Normal BMI

18.5–24.9 kg/m²

Overweight BMI

25.0–29.9 kg/m²

Obesity BMI

30.0 kg/m² or greater

Asian BMI overweight cutoff

23.0 kg/m²

Asian BMI obesity cutoff

25.0 kg/m²

BMI limitation

Does not distinguish between body fat muscle mass or bone

Obesity paradox

Some individuals with congestive heart failure have improved survival with BMI of 30 or greater

Waist-to-hip ratio

Waist circumference divided by hip circumference

WHR high-risk cutoff under age 60 females

Greater than 0.86

WHR high-risk cutoff under age 60 males

Greater than 0.95

WHR high-risk cutoff age 60–69 females

Greater than 0.90

WHR high-risk cutoff age 60–69 males

Greater than 1.03

Waist circumference

Can indicate obesity-related health risk and central obesity

Waist circumference compared with BMI

Can be superior to BMI for assessing obesity-related health risk

Circumference measurement rule

Take duplicate measurements and retest if they differ by more than 5 mm

Skinfold measurement

Estimates body fat percentage by measuring thickness of skinfolds

Skinfold principle

Subcutaneous fat is proportional to total body fat

Approximate subcutaneous fat

About one-third of total body fat

Skinfold accuracy

Approximately ±3.5% when proper technique and equations are used

Skinfold measurement side

Right side of the body

Skinfold caliper placement

1 cm away from the thumb and finger perpendicular to the skinfold

Skinfold reading time

Wait 1–2 seconds before reading the caliper

Skinfold duplicate measurement rule

Retest if duplicate measurements differ by more than 1–2 mm

Densitometry

Estimates body fat from whole-body density

Hydrodensitometry

Uses underwater weighing to measure body volume

Archimedes principle

An immersed body is buoyed by a force equal to the weight of water displaced

ADP

Air displacement plethysmography

ADP advantages

Quick comfortable automated noninvasive safe and accommodates many populations

DXA

Uses two low-level X-ray energy beams to assess body composition

BIA

Bioelectrical impedance analysis estimates body fat using electrical impedance

BIA principle

Fat contains little water and impedes electrical current while muscle conducts current well

Ultrasound body composition

Uses sound waves to directly measure subcutaneous fat thickness

CT and MRI

Imaging methods that can more accurately identify deep visceral fat

Body composition norms

There are no universally accepted norms

Good body fat range males

12–23% across a wide age spectrum

Good body fat range females

17–26% across a wide age spectrum

CRF

Cardiorespiratory fitness

CRF health importance

Low CRF is associated with increased premature death and CVD risk

AHA and CRF

The AHA recognizes CRF as a clinical vital sign

VO2max

Maximum volume of oxygen consumed per unit time

VO2max units

Typically expressed as mL/kg/min

VO2max components

Maximal cardiac output multiplied by arterial-venous oxygen difference

CPET

Gold standard measure of cardiorespiratory fitness

CPET measurements

Measures ventilation and expired oxygen and carbon dioxide during exercise

Peak VO2

Preferred term when a true VO2max cannot be confirmed

Maximal exercise test

Requires exercise to the point of volitional fatigue

Submaximal exercise test

Uses submaximal exercise responses to estimate CRF

Submaximal testing advantage

Lower cost potentially lower risk and less time than maximal testing

Submaximal HR steady state

Two consecutive stages with HR within 5 beats per minute

Submaximal testing HR assumption

There is a linear relationship between HR and work rate

Submaximal testing medication issue

HR-altering medications can affect the accuracy of CRF estimates

Exercise test minimum measurements

HR BP and RPE

Exercise test BP position

Arm should be supported at heart level and not gripping equipment

Exercise test termination SBP

Drop of 10 mm Hg or more with increased workload

Excessive BP termination criterion

SBP greater than 250 mm Hg and or DBP greater than 115 mm Hg

Other exercise test termination signs

Angina shortness of breath poor perfusion abnormal heart rhythm severe fatigue or request to stop

RPE

Rating of perceived exertion

Borg RPE scale

6–20 scale used to rate exercise intensity

Borg 6

No exertion at all

Borg 7

Extremely light

Borg 9

Very light

Borg 11

Light

Borg 13

Somewhat hard

Borg 15

Hard

Borg 17

Very hard

Borg 19

Extremely hard

Borg 20

Maximal exertion

Typical maximal RPE

18–19 out of 20