Exercise Testing

Question 1

Why do we undertake exercise testing?

Answer 1

To determine:

• exercise capacity/fitness
• disease risk
• differential diagnosis
• assessment of severity of disease
• pre-operative risk
• disability evaluation
• rehabilitation / exercise prescription
• effectiveness of therapy

Question 2

What type of physical activity is generally undertaken in exercise testing?

Answer 2

Most exercising testing occurs on a bike

• It is generally safer than running on a treadmill in case of fatigue or collapse
• Problem with cycling is that localised muscle fatigue in the quadriceps can occur before systemic fatigue occurs

Question 3

What it the measurement O₂ Pulse?

Answer 3

It is the amount of oxygen pumped per heartbeat

Question 4

What are modified Bruce protocols?

Answer 4

Modified Bruce protocols are sequential increases in the speed and grade of exercise testing in order to observe responses to exercise accoss different levels of activity

Designing the protocol is important because you want to prevent fatigue but stress the cardiovascular system enough to diagnostically evaluate it

Oxygen consumption increases with an increase in grade + speed of exercise

Question 5

What is the difference between VO2 max and VO2 peak?

Answer 5

VO2 peak is the highest value of oxygen consumption in an exercise test…

It may be that individual was unable to reach their VO2 max in that particualr exercise session (for some reason) in which case the VO2 peak does not equal their VO2 max.

Question 6

Is lactate produced only in anaerobic activity?

Answer 6

No

Some lactate is produced at sub-maximal VO2 where oxygen for aerobic respiration is amply available and delivered

This indicates that lactate can be produced aerobically - probably as a part of glycolysis

Question 7

What are some indirect tests of VO2 exercise capacity and performance?

Answer 7

Walk/run tests

20m shuttle run / Beep test

Harvard Step Test

PWC₁₅₀/PWC₁₇₀(how much power or work is required to reach a HR of 150/170 bpm)

Question 8

For what reasons is exercise testing most commonly ceased?

Answer 8

Fatigue/exhaustion

Drop in BP

Moderate to severe angina

Ataxia, dizziness, syncope

Dysrhythmias

ST segment changes

Shortness of breath beyond exercise norms

Question 9

What factor best predicts level of performance in endurance athletes?

Answer 9

VO₂max, lactate production and anaerobic threshold are all important factors in endurance performance.

VO₂sets the limits of potential performance, but the ability to actually use the oxygen provided is of greater importance to determining performance outcomes

Thus, muscle oxidative capacity is a greater predictor of endurance performance than VO₂max

Question 10

What is the relationship between lactate threshold and the amount of glycogen used by elite endurance cyclists?

Answer 10

The higher an individuals lactate threshold, the less glycogen an athlete utilises

Question 11

How can muscle strength be tested?

What is the association between muscular strength and mortality?

Answer 11

1 repetition maximum

Maximum voluntary contraction

(isometric, concentric, eccentric, isokinetic)

Higher muscular strength is associated with lower all cause mortality compared with lower muscle strength individuals