Integrated & Applied Studies Flashcards
Why is it difficult to measure how much energy life costs?
Methods can be invasive.
Individual may change behaviour.
Many factors in flux e.g. environment, age, illness etc.
What did original pedometers do?
Measured distance and number of steps directly.
What did early hip worn pedometers do?
Counted & measured movements of a small ball/pendulum.
What are examples of electronic forms of measuring movement?
GPS.
Triaxial accelerometer.
Electronic circuit version of a pedometer.
What do accelerometers measure?
True acceleration relative to freefall via g-force.
What do accelerometers behave like?
A damped spring.
Acceleration moves a mass until force by spring is equal to g force.
What do piezoelectric devices do?
Convert motion into an electric current.
What does electronic circuitry in accelerometers measure?
Current evolved.
How many planes can an accelerometer measure?
One.
Why do triaxial accelerometers have their name?
Because they can measure three axis of movement.
What approach to measuring heart rate is commonly used in physiology labs to measure HR during exercise?
Monitor picks up the ECG, converting it into HR.
What approach to measuring heart rate relies on the fact that heart rate increases with effort?
Measuring pulse of blood flow or oximetry.
What is oximetry?
Measuring of the percentage of oxygen-saturated haemoglobin in the blood via an oximeter.
What is haemoglobin?
A red protein responsible for transporting oxygen in blood.
Characteristics of a chest monitor for measuring HR?
Measures thorax displacement during breathing.
Relies on increased ventilation during increased exercise.
What do any measurements of energy expenditure require?
Lab-based interventions.
Advantages of lab-based interventions?
Easy to use.
Has applications to real life events.
Disadvantages of lab-based interventions?
Many assumptions.
Can’t be related to all ages/circumstances from a small group.
GPS?
Global positioning system
How does a GPS determine your position?
Uses triangulation.
Traingulation?
Involves determining the distances to at least three GPS satellites from the user’s GPS receiver.
Formula for the distance from a satellite?
velocity of light x time difference
What allows for greater precision of a GPS?
More satellite signals.
How is a GPS a way of measuring average velocity?
By knowing:
Your location
Distance travelled
The time
How is a GPS a way of calculating climb and descent?
Maps have contours of elevation.
Formula for force?
Mass x acceleration
Formula for work done?
Force x Distance
How can a GPS estimate work done?
If the software knows your mass it can calculate the work done to move a specific distance.
How can a GPS estimate calories burned?
Using assumptions.
Many apps available for computer/mobile devices e.g. fitbit
What do measures of PA need to work out the validity?
Some sort of reference measure.
What do measures of PA need to work out the precision?
Some measure of error.
What do measures of PA need to work out the day to day, person to person measures?
Some measure of repeatability.
What are ‘gold standards’?
Measures that allow you to tell the user how far away from the real measure the values your device gives.
Examples of ‘gold standards’?
Lab based measures of EE.
Free living EE.
What are the best measures for comparison of PA?
Direct & indirect calorimetry.
Doubly labelled water method.
