lecture 6 - Assessing Cardio-respiratory fitness Flashcards
Define CRF and the 3 areas involved
The ability of the circulatory, respiratory and muscular systems to supply oxygen during sustained physical activity
Integration
Communication
Co-operation
Why is CRF important
It’s a strong independent predictor of all cause mortality and CVD morbidity and mortality
As well as it being negatively correlated with developing glucose intolerance, high blood pressure and obesity
Positively correlated with the QOL and is a predictor of endurance performance
Why do we pre exercise screen and how do we do it
It identifies those with medical conditions who may be at an increase risk during exercise such as CVD or blood pressure
We use AHA or ASCM questionnaires
Describe the ACSM risk stratification factors
Low risk: men below 45 and women below 55 with 1 or less risk factor
Moderate risk men 45 or over women 55 or over with 2 or more risk factors
High risk 1 symptom or known disease
For each risk level, how much supervision should be given
Low risk no education or physical supervision
Moderate: medical before high intensity and supervision for high intensity
High risk: medical and supervision at any point
What is the gold measure for CRF
Maximal oxygen uptake, usually on the treadmill
How is VO2 max calculated
When the oxygen consumption levels off despite an increase in work rate
Or
Blood lactate is greater than 8mmol
RER is greater than 1 or 1.15
Hr within 10beats of maximal predicted hr
RPE greater than 18
Is maximal oxygen uptake a valid measurement (Secondary criteria)
VO2 plateau is rarely observed
RER is highly variable and depends on diet anxiety
Age predicted HR is often inaccurate and blood lactate levels are dependent on measurement time and type of exercise
Because direct measurement of VO2 max is often not practical how else do we manage to measure it
We can use equations used from submaximal stages, eg measure HR up until 85% of maximal heart rate and then extrapolate
Downside is that other factors affect sub max HR response
What are the 4 types of exercise protocol
Balke which has constant speed but grade increases 1% every 1 min
Bruce is the same but every 3mins
Ellestad increases speed until 10min then 1 grade increase then speed
A strand same speed increased grade every 2.5 mins
Why might we use a treadmill for VO2 max
Replicates natural activities Greater muscle mass utilisation Lower BP response Accommodates a wide range of participants Based on 85%
Why might we use a cycle ergo meter for VO2 max
Body weight is supported if there are orthopaedic limitations
Work rate depends on resistance and pedal rate which is easily quantifiable
Based on a YMCA protocol
Why might we use field tests for estimating CRF
Uses natural low cost activities
Can test large groups
Physiological responses may be difficult to measure
Motivation is a large factor
Why might we use maximal run tests
Coopers 12 min run
Based on a linear relationship between running speed and oxygen cost
What does the ASCM recommend
3-5 sessions per week 20-60min sessions 40-85% max VO2
