MEASURING EXERCISE INTENSITIES AND ENERGY USAGE

Question 1

Why is measuring exercise intensities valuable

Answer 1

because it gives an indication of
- sustainability of performance (eg. find someones vo2 max, team sports fitness)
- safety of exercise in inactive or clinical populations
- severity, progression, management of disease
- nature and magnitude of stimulus for adaption - hardest parameter to quantify, is intensity

Question 2

Relationship between Running Velocity and Energy Usage

Answer 2

linear - when you double your running velocity your energy usage will also double

Question 3

Ventilatory Thresholds

Answer 3

• don’t produce much power but this is more sustainable
• when the intensity increase more type 2 fibres are used more which becomes more stable
• as intensity increase so does ventilation
• as you start to breathe more = more consequences
• the more fit you are the more 02 you get our of each breathe, but their becomes a time when you breathe more than you need to

Question 4

Anaerobic Threshold

Answer 4

• is usually the second threshold in a vo2 max
• increase in ventilation and lactate production

Question 5

thresholds are very hard to _____ and to ______

Answer 5

identify and interpret

Question 6

Power vs Endurance VO2 max lactate

Answer 6

powerful people have more type 2 fibres as not so aerobically trained, and type 2 fibres produce more lactate, so more acidic as turning over ATP

it is the opposite for type 1 fibres

Question 7

Smart Watches and Intensity Zones

Answer 7

not validated indicators of intensity, for many things but for exercise intensities they do this well

Question 8

Phones and Exercise intensity

Answer 8

use some accelerometers with some sort of biophysical. they put together many measurements

Question 9

Pros and Cons of Smart Devices and Exercise Intensities

Answer 9

pros
- measure fitness testing/performance
- provide motivation
- track your intensity
- relatively cheap
- have a gps
- pretty validated for energy use

cons
- they take large data set with your info
- false ideas
- physiological dependence
- tell you things about your thresholds that aren’t validated

Question 10

3 other useful measures of Exercise intensity

Answer 10

1. respiratory exchange ratio
2. METS
   activity met rate/resting met rate
   they are usually used in a health context
3. RPE

Question 11

What 3 ways is HR used to indicate intensity

Answer 11

1. heart rate bpm - easy
2. relative to max
   %HR MAX = HR/HR MAX *100
   better indicater of relative exertion
3. HR Range
   best indicator of exertion
   %HRR = (HR-HR Rest)/(HR Max - HR Rest) * 100

Question 12

Absolute vs Relative VO2 Max

Answer 12

absolute means their one assessment, whereas relative is compared to other variables
ones absolute will be different to each other but their relative due to weight will be similar and determines ones energy usage

Question 13

Exercise Economy and Efficiency

Answer 13

these are both closely related

economy - energy expended to maintain constant speed or per unit distance travelled 1kcal/kg/km

efficiency - metabolic cost of work, this is how much you get out for what you put in

Question 14

Factors that effect exercise economy and efficiency

Answer 14

• speed of movement
• exercise work rate
• fibre composition
• training status
• posture and familiarity with activity or ergometer (the more trained the better)

Question 15

Why measure Energy Usage

Answer 15

• the energy use of exercise, many things effect this, eg the fitter you are the more energy you use as you train harder
• when using aerobic power, how does your body function in response to this
• is 1 aspect and 1 measure of exercise intensity
• daily energy usage

Question 16

Why is fitness levels reports no very usefull

Answer 16

fit people overstate their level and unfit people understate their fitness level

Question 17

Measuring energy usage and Std error of estimate

Answer 17

doubly labelled water - 1-2%
smart devices - 3%
accelerometers + activity etc - 10%

Question 18

Why is energy usage hard to measure

Answer 18

we are not 100% efficient at turning chemical to mechanical energy. 2/3 of energy is lost to make ATP so work rate is only 25% efficient at best. we can only measure this in a steady state

Question 19

Energy Usage is ultimately net aerobic and therefore measurable ….

Answer 19

O2 into body cells to make ATP which then result in heat and mechanical energy, CO2 and H2O

Question 20

Calorimetry

Answer 20

the measurement of metabolic energy transformation

= heat production of no net mechanical work

Question 21

Direct Calorimetry

Answer 21

1. bomb - measures energy released from combustion of all food stuff
2. whole body - measures body heat production, in a sealed insulated unit. very rarely done

Question 22

Indirect Calorimtry

Answer 22

indirectly measure rate of energy use by measuring rate of O2 consumed - VO2 Max, measuring the rate of VO2 and VCO2 produced

Question 23

How much make o2 do you get from each fuel

Answer 23

carb is the most at 21, then mixed diet at 20 and then fat at 19

if you are fasting you burn more fat then cabrs

Question 24

If O2 is constrained in high intensity exercise then why do we use an increase in carb metabolism

Answer 24

1. better energy return than fat
2. run glycolysis

Question 25

3 things to think about when estimating caloric equivalent from RER

Answer 25

- respiratory quotient - RER reflects RQ with aerobic metabolism - RER>1 reflect loss of CO2

Question 26

Why should you not take much notice from your device when they say you are in a fat burning zone

Answer 26

no matter when your exercising you are always burning fat but at higher intensity you burn more carb and at low intensity you burn more fat