Phys Lab Flashcards
Describe VO2 maximal exercise test and drawbacks
Low = increased risk of CVD and premature mortality
Direct determination via a maximal exercise test and measuring expired expired gases - O2, Co2 and gas volumes (indirect calorimetry)
Not suitable for individuals with high risk CVD
Lack of specialist equipment or trained personel
Cost of equipment and need for system calibration
Decribe the 4 methods for predicting VO2 max
The Bruce treadmill protocol - maximal graded exercise test
The Astrand - Ryhming cycle ergometer test - submaximal test
The Chester Step Test - submaximal test
Questionnaire (no exercise)
Safe conduct guidline
Complete a PAR-Q (physical activity readiness questionnaire)
Informed consent form sign
1) Ensure that the treadmill or ergometer is safe
2) Describe all procedures fully to the participant and provide a written summary (Participant Information Sheet)
3) Familiarise the participant with all equipment to be used]
4) Give the participant opportunity to ask questions
5) Ensure that the participant knows that it is his/her responsibility to inform the experimenter if they are in difficulties during the test.
6) Watch the patient closely during and 10 minutes afterwards
7) Give the participant time to warm up and cool down after exercise
behave calmly
Use simple language
Describe the Bruce Treadmill protocol and benefits/ drawbacks
Maximal exercise stress test.
Performed until exhaustion or signs and symptoms.
Duration used to predict VO2 max.
Every 3 minutes (to end of 27), % grade increased from 10 by 2 and speed increased by .8-1.5km/h.
Non invasive
Suspected heart disease patients
Can give overestimation if heavy use of handrail
What is monitored during the Bruce treadmill protocol?
HR, rating of perceived exertion (RPE), ECG, BP, clinical signs and patient symptoms.
Often difficult to measure obs
How is duration of the Bruce treadmill protocol used to predict VO2max?
Using equation
Fraction of a minute needs to be calculate (
Describe the Astrand-Rhyming cycle ergometer test
Submaximal stress test
Heart rate is used to predict VO2 max when working at a set heart rate.
A nomogram is uses gender, HR and Work load to calculate VO2 max. This is then multiplied by a correction factor to adjust for age
The participant works at 50rpm for 6 minutes. HR is taken at minute 5 and minute 6 and an average is taken.
Unconditioned male uses 300 or 600 kg.m.min-1 = 50-100Watt
Conditioned male 600-900= 100-150
Female = 300-450
cond female = 450-600
Stop at 70%HR reserve / 85% HRmax.
Goal to get HR between 125-170
PES used also
What assumptions need to be met for an accurate estimate of VO2 max (5)
1) steady state heart rate is reached for each exercise work rate
2) Linear relationship between WR and HR
3) Predicted and actual max HR are minimal difference
4) Mechanical efficiency is the same for everyone
5) No caffeine, drugs, stress, dehydration, hot as all of these affect heart rate
How is kg.m.min-1 calculated?
flywheel reveloves at 6m per revolution. 50RPM. 1kg x 6 x 50 = 300kg.m.min
Describe the Chester step test
Step in time to muscle
Low resource, don’t need specialists/ ergometers
5 x 2min stages
What does the chester step test require
CD player (metronome), HR monitor, stop watch, graph paper/nomogram, Borg 6-20RPE scale, steps
What are the heights of the step in the Chester step test
30cm <40 regular MVPA performed
25cm >40 regular MVPA performed
20cm <40 little or no activity/ moderatel overweight
15cm >40 little or no activity/ moderately overweight
>60 then 15-20cm
What should be done prior to the Chester step test
Measure resting HR Ask age Calculate predicted max HR Explain -step on and off in time with tape -Every 2 mins HR and RPE will be checked and pace will increase -Can change lead leg - Continue until 80% or RPE >=14 -Tired, dizziy, faint, breathless then stop Demonstrate technique
How is the Chester step test conducted?
Start stopwatch Ensure timing is correct Ensure patient doesn have hands on knees Take HR and RPE Repeat 3 levels are needed for valid outcome
How do you interpret Chester step test?
Plot HR on graph paper taking into accont height
Draw linear line of best fit (do not use if <50% heart rate max)
INterpolate maximal O2 from age predicted max HR
Decribe non-exercise VO2 max estimation
Used questionaires e.g. CHarles.
Uses sex, BMI, age, Percieved fitness and percieved PA
PFA - Percieved functional ability based on pace at which you could run 1 mile continuously (not too fast or slow) - just right for you = 1-13
Also pace at which could run/ walk 3 miles without getting out of breath or overly fatigued 1-13
PA-R habitual PA
1-10 based on light, mod, vig activity average over last 6 months
What can be done prior to test?
Forms and sheets ready Calibrate equipment Organsie so that same muscle group is not stressed continually Consent form Maintain temp 20-22 and humidity <60% Obtain HR, BP, height, weight, body comp Note use of BBs or drugs with HR effect
What should be done between tests?
Allow HR and BP to return to baseline
Define cardiorespiratory fitness
Ability to perform large muscle dynamic MV intensity exercise for prolonged periods of time
What physiological factors is VO2 max dependent on?
CO and arterial to venous pressure gradient
How do you know you have obtained VO2 in test?
O2 consumption at a steady state
Difference between VO2 max and peak VO2?
Peak = not O2 steady state - most pulmonary/ CVS patients
When can submax be used in MI patients
4-hrs after MI
Why is HR in submax not directly linked to VO2? one way to make this better
due to environment, diet and behaviour
e.g. allow a practice to reduce effects of anxiety.
Avoid caffeine.
Allow HR to reach steady state
Describe field testing of VO2max - benefits and drawbacks
Running/walking in predetermined distance or time. Cooper 12 min test 1.5mile run Submax but may be max for some Unmonitored obs Motivation and pacing ability effects
Why can a practice motor driven treadmill sub max test be useful?
Reduce anxiety
Positives and negatives of cycle ergometer tests
People less familiar to this type - may be inefficient, may cause muscle fatigue that limits.
Needs calibration
Needs proper pedal rate
MOre transportable, easier to take obs, cheaper
Positives and negatives of step testing
not good for coridation/ balance problems
Some may exceed maximal capacity
Inexpensive
Describe submax treadmill tests
Stop at 70HRR or 85% HRmax
3min or longer ensures steady HR
Test termination criteria
SBP decrease 10 with increase in work load. HR fails to increase (estimate may be wrong) Participant asks to stop Clinical symptoms Arrhythmias BP >250/115 Manifestations of severe fatigue Failing of equipemt
Purpose of muscular strength and endurance (muscular fitness) programs
Increase QoL, ADL, prevent muscle and bone wasting with age, increase lean body mass, beneficial CVS RFs, good for glucose tolerance
Rationale for muscular fitness testing
Track progress, show improvements/ motivate from baseline
Principles of muscular fitness testing
Specific to group, action, velocity, equipment and ROM
No single test
Muscular strength and endurance
Maintain full ROM, speed, strict posture, spotters when neccessary, equipment familliisation, warm up aerobic and static streches and several light intensity reps
Change based on absolute value of external resistance or just kg.
Generalisaility when comparing e.g. diff biomechs of machines
Describe testing of muscular stregth and types
Resistance overcome or met
Static or dynamic
Describe static strength testing
Resistance handgrip dynamometers or static cable tensiometers
Specific to muscle group and joint angle so limited in describing overall strength
Peak force development = maximum voluntary contraction (MVC)
Describe dynamic muscular strength testing
Typically 1Rm ro 4-8RM
Bench or shoulder for upper body
Lower body leg press or extension
How to determine 1RM
Warm up - submax reps to determine 1RM range
4 trials with 3-5mins rest - progressively increasing weight until cannot complete (initial is 50-70% capacity)
Final is absolute 1RM
Describe muscular endurance assessment
Absolute or relative (%of 1RM)
e.g. 70% e.g. curl up test or push up
Also duration of static muscle action
Uses of muscular fitness testing in older adults and example of one
Highlight/ account for physical limitations to design programs to account for this
Increase independent life and life expectancy
Senior fitness test - 30 chair stand test and sing arm curl.
Describe strength testing in coronary prone clients/ patients
Mod intensity resistnace training 2-3d/week
Prevent and manage a variety of chronic medical condition, modify RFs, enhance psychosocial well-being.
Not sev symptoms cna do mod intensity 10-15 reps
Elicit HR and BP responses in normal limits (pressor responses)
Describe muscular fitness testing in children and adolescents and purposes, from what age?
INcrease posture, self confidence, lean body mass, reduce risk of injury, enhance moor performance
7-8yr can be ok
Push up an abdominal curl up
Describe testing of flexibility
Ability to move joint through its full ROM
Athletic performance is liked and AoDL
Damage can occur beyond ROM
Joint specific
LAb tests express in degrees - objective
Screening use visual estimates (not good)
What does flexibility depend on
Joint capsule
Muscular viscosity
Adequate warm up
Compliance of other tissues e.g. tendon/ lig
Describe the sit and reach test
Sitting ith knees in extension how far can fingertips reach forward
Due to hips and haps and lower back
Describe a comprehense health fitness evlation
Prescreening/ risk classification Resting HR, BP, BMI, ECG Body comp- waist and skinfold Cardioresp fitness Muscular strength Musc endurance Flexibility
Describe the townsend score
Scale of socioeconomic status dependent on post code. Takes into account:
Non-car ownership (%)
Non-home ownership (%)
Household overcrowding
Unemployment (% over 16 and economically active).
Based on census data
The factors in the Framingham Heart study multivariate algorithm
7 factors Age, HDL Total cholesterol BP BP medication history Diabetes status Smoking status
What does the Framingham risk score do? When is an intervention needed?
10 year risk of development of CHD
Needed if >20%
What is needed to measure cholesterol levels? What needs to be checked?
Cardiocheck point-of-care bioanalyser, glvoes, apron, warm water, gause, lancets, sterile wipe, sharps bin, yellow bag
Why is smoking bad?
Endothelial damage Raises BP Thickens blood Strains heart Damages lungs - cancer, COPD, asthma
Describe spirometry uses, and key points?
Fully respire as quick as possible after a full inhalation
Repeat 3 times - take highest or 2 readings within 5% of each other
Mouth tight seal
Use nomograph with age and height
Used for diagnosis and monitoring
Abnormal spirometry findings?
FVC <80% of predicted
FEV1 <80%
FEV1/FVC <0.7
Describe the QRISK-2 Calculator RFs included
from 2 million medical records. Same as Framingham but tc/HDL instead Fx - event <60 BMI Self assigned ethnicity CKD AF RA Deprivation
Chance of having CHD or stroke
Why might QRISK be better than Framingham?
Includes stroke.
Based on UK population
What are the goals of the new ACSM exercise pre-participation screening process?
Identify those that need medical clearance or with disease who may benefit from a medically supervised program or exclusion
Reduce barriers to a regular exercise program
What factors determine course of action for preparticipation screening
Current exericse participation
Known signs or symptoms or CVS, metabolic or renal disease
Desired exercise intensity
What problems are apparent with an overly rigorous pre-exercise screening process?
Excessive physician referrals - barrier to participation
Exercise is safe for most people and has many benefits
CVS events are often preeded by warning signs/ symptoms
What physiological processes are thought to underpin exercise-induced cardiac events in young people and adults (<35)
Structural abnormalities
Conduction disorders
HCM - Impair function of heart and can lead to arrhythmias e.g. VF. Also thickened walls compromise function - exercise thickens too.
According to Kim et al 2012 what is the CA and SCA death incidence rates in marathon and 1/2 marathon rnners
1.01 per 100,000 vs 0.27 per 100,000
Higher if older and male
Describe the PAR-Q
Physical activity readiness questionnaire
7 questions
Yes to any one of them = physician referral
Questions in the PAR-Q
1 - Doctor said you need to consult before exercising or do you have CVD?
2- Chest pain on exertion?
3- Chest pain at rest over last month?
4 - Medication for BP or CVD?
5 - Joint or bone problem that may get worse
6- Dizziness causing loss of coordination of LOC?
7 - Any other reason?
What is the NHS health check
Free check for people ages 40-74. Get letter every 5 years without a pre-existing condition.
Uses clinRisk - based on QRISK-2.
Participant instructions prior to exercise testing
No food, alc, caffeine or tobacco in last 3 hrs
Rested and avoid exertion on that day
Free clothing
Make aware they will be tired - driving ect
If diagnostic may need to discontinue meds
Bring a list of meds
Drink lots of fluids in 24hrs proceeding
Stages of informed consent
Verbally describe process. Risk and benefits, they can withdraw at any time, check understanding, opportunity to ask questions, use of medical records.
Procedure BMI
Also known as Quetelet,
mass/ height 2
Unknown reasons BMI >30 is worse (maybe not in mortality) but metabolic syndrome.
Use table to calculate % fat
Positives BMI
Simple, good for populations
Good correlation with fattness in large groups
Limitations BMI
+/- 5%
Bodybuilders
Not accurate for individual
Positives Waist circum
better measure of central fat - used with BMI as central fat is a more potent RF.
Accuracy 2.5-4% if similar to gen pop and girth measurements are precice
Describe Waist circum measurements
Measured at narrowest point between xiphoid and umbilicus.
Do not compress SC fat
Allow time for skin to regain nomral between - duplicate >5mm diff then do 3.
Often used with hip or with BMI- several methods.
Men >102cm and WOmen 88cm = increased risk
Limitations waist circum
similar to skinfold and obvious
Describe Skinfold
Tension should be 12g.mm-2
Right side of body
Caliped directly onto skin, 1cm away drom thumb and finger perpendicular to thefold and halfway between the crest and base of the fold.
Pinch maintained while reading the caliper
Wait 1-2s before reading the caliper
Take duplicate at each site and retest if not within 1-2mm
Rotate or allow time for skin to regain normal texture and thickness
Positive skinfold
Correlates well with hydrodensitometry as SC fat proportional to total fat.
+/- 3.5% accuracy if good tehnique and equation
Negative skinfold
Very dependent on technician
Variations in SC fat with sex and race - equations pop specific
Depends on expetise of technician, need training and practice
Not good in extremes
Describe Bio-impedance analysis
Based on estimation of total body water
Passing a small electric current through the body and determining resistance
Fat free masss is more hydrated than fat and bone so less resistance
Positive Bio-impedance analysis
Similar to skinfold in accuracy if protocol is followed
Can be used routinely
Negative Bio-impedance analysis
Need normal hydration, temp, prior PA.
Only valid for population setting
Limited in obese due to different water distribution
Needs more research
Positive Hydrostatic weighing
Very accurate
Describe Hydrostatic weighing
Loss of weight = weight of water displaced.
An object is buoyed by a counterforce equal to the weight of the water displaced.
If one person with same mass but fatter, will displace more water, will have more buoyancy, will weigh less underwater.
Standard method for body comp
Negative Hydrostatic weighing
Requires special equipment, accurate measurement of residual vol.
Pop specifc formulas
Significant cooperation by subject
Anxiety
Describe Plethysmography
Air rather than water displacement e.g. dual chamer that measures body volume by changes in pressure in a closed chamber
Positive Plethysmography
Now well established, reduces anxiety with hydrodensitometry
Negative plethysmography
Needs chamber, staff ect.
Describe DEXA
Duel-energy xray absorptiometry.
2 XR beams are used to scan the bod and measure the absorption.
Patient lies supine
12 minutes
to scan
Software reconstructs attenuated beams
Produces image and quantifies bone mineral content, total fat and FFm
Pos DeXA
little radiation - 2 bananas or 15 on flight.
Neg DEXA
Xrays
Describe MRI
x
Pos MRI
Non invasive, Not hazardous Hydrogen nuclei excited via electromagnetis Differences of water and lipid Highly precise Breakdown of segments
Neg MRI
Accessibility and cost - just research
What is the obesity paradox?
HF patients - improved surviva when BMI >30
Describe WHR and uses
Hips - Buttocks at widest part. Very high for men WHR >.95 and .86 for ladies. For 60-69yr olds it's >1.03 and 0.9. Used with BMI for risk
How much does sub cut fat account for?
Varies in pops but normally 1/3 of total fat
Describe the sites of the skinfold tests.
Triceps - vert, halfway between olcranon and acromium, midline
Biceps - vert 1cm above triceps in midline.
Pectoral - diagonal halfway between nipple and ant ax line and 1/3 in women
Abdominal- vert - 2cm right of umbilicus
Subscapular - diagonal 45 deg 1-2cm below inferior angle
Suprailiac - diagnoal with IC in ant ax line superior to crest
thigh - vert on ant midline halfway between inguinal crease and patella
Calf - medial - vertical fold at maxi circum
How to convert body density to body comp?
Use pop specific formulas
Total body electric conductivity (TOBEC) draw back
Cost and need for highly trained personnel
Describe body comp norms
No universal norms
Done on % values
Exact for optimal health but 10-22 and 20-33% suggested
How much weight lost to be “weight loss” how much is clinically significant
> 5-10%
<3% = weight maintainence
How much PA for weight loss?
> 250mins
Less clear evidence for 150-250 may lose in some and with diet but minimal amount.
Fitness determines size of weight loss
How much PA to prevent weight gain?
150-250 MPA
How much PA to improve weight maintenance after loss? quality of evidence?
> 250 (maybe more)
Lack of RCTs
How can a fat guy achieve weight loss best? How is BMI 45 different to 32?
Surgery Diet Drugs Exericse CAnt burn as many calories if less fit.
What is Nonexercise activity thermalgenesis? Different from lifestyle forms of PA?
All energy burned not from sleeping, eating or planned exercise programs
Lifestyle PA then same (PA not in structured period of exercise)
Ways of measuring Nonexercise activity thermogenesis?
Subjective not as good.
Objective 0 PEdo, acceloerometer, inclinometer and doubly labelled water
Benefits of resistance training for weight loss?
Increase fat free mass
Maybe increase 24 hr RMR.
Combination with aerobic may be better for fat loss and prevention of lean tissue loss (high protein can help)
Improvements in CVD RFs in the abscence of weight loss e.g. HDL, LDL, TG, insulin, BP.
Not enough evidence for roe in chronic disease
Difference between RMR and BMR
BMR = minimal amount of energy required to sustain vital functions
RMR = Energy expenditure at rest (increase with digestion, post exercise ect.)
‘Thermogenic effect of feeding’ separate
Only difference between RMR and BMR is that BMR is more accurate metab rate
How is RMR measured?
3-4 hours after a light meal without prior PA (higher than BMR measured at rest without food in past 12 hours)
How does energy expenditure vary with O2 consumption?
Seated for 10 mins
Quietly for 5 mins
Collect inspired air into a Douglas bag for further 5 minutes
Breathed out using O2/ CO2 analyser
Approximate RMR, who may this be lower for?
1kcal/kg/hr
females, older, overweight
Approximate equations for calculating RMR
Female = (10 x kg) + (6.25 x cm) -161 Men= (10 x kg) + (6.25x cm) +5
How can energy expenditure in PA be calculated?
MET x duration in hours x kg.
MET from the compendium of Physical activities codes from Arizona state university.
MET = multiple of RMR
= 1 kcal per kg per hr or 3.5ml/kg/min
NET Pa from compendium?
MET - 1.
How to estimate energy expenditure at 60% VO2 max?
Estimate VO2 max
Calculate 60% in L/hr (use body weight and ml to L)
x5 = kcal per hr
1MET = 1 kcal per kg. per hr so find out
Note 60% is maximum sustainable aerobic exercise intensity
Energy expenditure directly from MET calculation? VAriation?
MET x kg x duration = kcal
Variation due to body weight and fat Age Fitness Genetics Sex MEchanical effcience and environmental conditions
Purposes of Compendium and update in 2011
Quantify the energy cost of a wide variety of PA
Enhance comparability of results across studies using self report PA
Major headings which organise PA by purpose e.g. leisure, transportation, occupation
