Exercise for Diagnosis: Principles of Exercise Testing

Question 1

ST depression is a marker of

Answer 1

myocardial ischaemia

Question 2

Exercise testing mainly focuses on

Answer 2

cardiopulmonary disease

Question 3

What are reasons for exercise testing?

Answer 3

exercise capacity/fitness; disease risk (METs); differential diagnosis (pulmonary vs cardiac vs vascular); assessment of disease severity; pre-op risk (frailty VO2max is 18mL O2/kg/min); disability evaluation; rehab/exercise prescription (to Rx %max); effectiveness of an intervention/therapy/exercise/surgery/medication

Question 4

What is the Bruce protocol?

Answer 4

4 stages of increasing treadmill speed and grade (10%-22%)

Question 5

What are modified Bruce protocols?

Answer 5

increasing grade progressively (not both speed and grade) making the test longer; or smaller but more increases in grade and speed

Question 6

What is a ramp protocol?

Answer 6

Increasing workload continuously

Question 7

Ramp protocols show what with regards to O2 consumption?

Answer 7

continuous rise in O2 consumption measured breath by breath

Question 8

What is a one minute step protocol?

Answer 8

increasing workload each minute, similar to ramp

Question 9

What does a two-minute step protocol show with regards to O2 consumption?

Answer 9

shows an increase in O2 consumption then levelling off with each increase in workload

Question 10

What is the benefit of starting with a step protocol then using ramp?

Answer 10

achieve steady states to give an idea of VO2 - PO relationship then ramp to fatigue - avoid MSK fatigue but adequately stress the CV-respiratory system

Question 11

What is VO2 peak?

Answer 11

The highest VO2 measurable during a test

Question 12

What are the criteria for VO2 max?

Answer 12

reaching age-predicted maximal HR; RER greater than 1.2 (significant CO2 buffering of metabolic acidosis); and VO2 does not increase by more than a few mL/kg with an increase in workload

Question 13

As exercise intensity increases, lactate

Answer 13

increases, often exponentially

Question 14

In more active groups, the lactate curve shifts

Answer 14

Right - ie trained muscle reaches lactate threshold later

Question 15

In someone with heart disease, the lactate curve shfits

Answer 15

Left - ie impaired O2 delivery to the muscle causing lactic acid production

Question 16

What are indirect exercise tests?

Answer 16

walk/run (6/12min walk) tests; beep test/20m shuttle run; using submax HR responses to predict VO2 max; VO2 - HR relationships during cycling (is HR decreased at same PO after training); harvard step test; PWC 150 and PWC 170 = physical working capacity - what PO do you need to get to HR 150 or 170 (fitter = higher PO to reach 150 or 170)

Question 17

What is the limitation to extrapolating VO2 max from submaximal testing?

Answer 17

differences in the HR response - slope can differ between trained and untrained; max HR can change due to changes in intrinsic HR; individual differences - some increase exponentially, others hyperbolically (ie non-linearly)

Question 18

VO2 max is limited by

Answer 18

O2 delivery; not so much mitochondrial oxidative capacity

Question 19

Fuel choice is influenced by

Answer 19

mitochondrial capacity

Question 20

Increasing mitochondria in muscle reduces reliance on which fuel?

Answer 20

CHO

Question 21

T/F Exercise performance is purely dictated by VO2 max

Answer 21

False; ability to use a high proportion of VO2 max for a long period of time determines performance

Question 22

What determines performance?

Answer 22

The ability to use a high proportion of VO2 max for long periods of time, rather than just a high VO2 max itself

Question 23

Ability to exercise at high proportion of VO2 max is determined by

Answer 23

ability to exercise at high intensity without producing a lot of lactate (because this means you are depleting glycogen)

Question 24

Muscle pyruvate oxidase assay measures

Answer 24

oxidative capacity

Question 25

Endurance is more related to _____________ while VO2 max is more related to ______________

Answer 25

oxidative capacity (mitochondria); O2 carrying capacity (delivery)

Question 26

Lactate threshold is more highly correlated with

Answer 26

muscle oxidative capacity than VO2 max

Question 27

T/F Trained individuals have a high VO2 max bc they have high oxidative capacity

Answer 27

False; may not be causal - trained indv have more mitochondria tf a higher oxidative capacity and generally also have high VO2 max

Question 28

Higher lactate threshold = ________ glycogen use

Answer 28

lower

Question 29

Higher lactate threshold is associated with

Answer 29

lower glycogen use and tf longer time to fatigue; higher lactate threshold means less glycogen is used at a given exercise intensity OR for a given glycogen use you can exercise at a higher intensity

Question 30

How can muscle strength be tested?

Answer 30

1 repetition maximums (RM); maximum voluntary contractions (MVC); can train with isometric, concentric/eccentric, isokinetic (velocity is controlled)