KNES320 LAB #1 SUMMER

electronic motion sensor device

what is a pedometer

how does a pedometer work

as a metal pendulum where a weighted hammer on one end creates a counting current and taking a step completes circuit adding to a clock and then the circuit is broken

pros of pedometer

inexpensive, easy, few errors

cons of pedometer

not accurate for some activities, no frequency, intensity or duration, can misread due to improper usage

electronic sensors detecting and reading acceleration from movement done, used in smartphones and fitbits

what is an accelerometer

how does an accelerometer work

measures real-time acceleration by detecting movement in anteroposterio, mediolateral, and vertical body planes

the sensors for an accelerometer sends signals that are ____________

proportional to muscular force

pros of accelerometer

reliable, easy, can distinguish, measure activity intensity

cons of accelerometer

temp sensitive, not accurate for some activities, only measure based on which body parts is used

electronic activity tracker worn as a watch

what is a fitbit

how does a fitbit work

uses a 3 axis accelerometer to count

____ x ____ = distance traveled and _______ is identified by height and sex

steps x strength, stride length

fitbits uses a _____ that detects _____

altimeter sensor, elevation

how does fitbit calculate calorie burn

combining bmr and activity data

pros of fitbits

provide real time data, measures hr, sleep rythm, etc

cons of fitbits

expensive, inaccurate measurement

measure amount of energy needed for specific task

what is MET

how does MET work

measures body’s O2 consumption rate as energy index expands where 1 MET = resting

1 MET = ______

3.5 mL O2/kg/min

light intensity MET

< 3

moderate intensity MET

3-6

vigorous intensity MET

> 6

pros of MET

simple, practical, giveO2 usage approx compared to avg resting rate, help to know which activity burns the most calories

cons of MET

standard measurement, doesnt take other factors into account, needs extra calculations

how is adipose tissue essential

necessary to sustain life

where is adipose tissue found

bone marrow, some organs, and cns

females require ____ adipose tissue

more

how can adipose tissue not be essential

becoming an energy storage as fat

where can adipose tissue fat storage be found

intramuscular, intermuscular, visceral, and subcutaneous depots

INTRAmuscular depot

in muscle fibers/ cells

INTERmuscular depot

between muscles

Visceral depots

surround organs

SUBcutaneous depots

beneath the skin

direct way to measure adipose tissue

most accurate but not practical; use cadavers

indirect way to measure adipose tissue

less valid, gives estimate; use antropometric, bia, skinfolds, air displacement plethysmography

what are the units for BMI

weight: kg, height: m²

bmi conversions

1 lbs = 0.45 kg or 1 kg = 2.2 lbs

1 cm = 0.01 m or 1 m = 100 cm (DONT FORGET TO ² AFTER)

how to calculate BMi

weight kg / height m²

BMI classifications

underweight: <18.5

normal: 18.5-24.9

overweight: 25-29.9

obesity 1: 30-34.9

obesity 2: 35-39.9

obesity 3: >40

why is there a J shaped curve for BMI classification health risks

being underweight can lead to significant health issues too as you aren’t getting enough nutrients to sustain daily activities

what is the purpose of assessing waist circumference

to access subcutaneous and intraabdominal fat, take 2 trials

waist circumference ratio

waist cm / hip cm

which fat pattern caries higher heath risks

male android

where is the waist and hip measured at

waist: narrowest part, hip: widest part

waist risk classifications

very low women: <70 male: <80

low women: 70-89 male: 80-99

high women: 90-110 male: 99-120

very high women: >110 male >120

how does BIA work

an electrical current will flow through body at certain speed based on composition

what does BIA determine

flow resistance

how does muscle and fat react to BIA and what does this mean

water in muscle conducts electricity while fat resist, faster conductivity = lower body fat while slower conductivity = higher body fat

how to prep for BIA and skinfolds test

be properly hydrated and abstain from exercise 3-4 hours prior

pros of BIA

quick, easy, for large sample size, considers other factors

cons of BIA

assumes hydration, inaccurate for under or over weight, estimates lower body composition

how to use BIA

input factors and extend arms to grasp handles

how does skinfolds test work

measure subcutaneous fat based on assumption 1/3 of total fat is subcutaneous

how to do skinfolds test

“pinch” areas either vertical or diagonal

why is hydration and avoiding exercise essential for the skinfolds test

dehydration reduce skin by 12%, blood flow from exercise causes inflation

why is relaxing muscles and avoiding lotion essential for the skinfolds test

muscle contraction changes measurement, lotion makes it unable to properly grip

women skinfolds sites and direction grip

triceps (vertical), superiliac (diagonal), thigh (vertical)

men skinfolds sites and direction grip

chest (diagonal), abdomen (vertical), thigh (vertical)

what is densitometry

application of body density to derive body composition by mass (g) / volume (mL)

how to get total mass

total mass = fat mass + fat—free mass

assumptions of densitometry

separate densities are additive, densities are consistent overall, tissue proportion are consistent

how does the bodpod work

dual chambered plethysmograph that uses pressure-volume relationship between the front test chamber and rear reference chamber to estimate body volume

subtract the subject volume from interior volume

pros of bodpod

easy, special populations, validity, quick

cons of bodpod

expensive, assumes constant density of ffm and fat

how to prep for bodpod

no intake or exercise at least 3 hrs prior, no lotion or jewerly, wear spandex or swimsuit

how does hydrodensitometry work

body fully submerged underwater where loss of weight in water is equal to weight of volume of water displaced

pros of hydrodensitometry

accurate, gold standard

cons of hydrodensitometry

subject dependent, timely, expensive, assumes constant density

fat vs lean mass underwater

fat is less dense than fat-free mass as it occupies more space, making it weigh less underwater