Presented by Chris Hudd - St Leonard's College · Maximum oxygen uptake, or VO 2 max, represents...

transcript

Presented by Chris Hudd

Study design dot points:• oxygen uptake at rest, and during exercise and recovery, including oxygen deficit,

steady state, and excess post-exercise oxygen consumption.

Breathe

Source: https://www.youtube.com/watch?v=rmHDhAohJlQ

Oxygen uptakeTheory summary

Oxygen uptake, or VO2, represents the volume of oxygen able to be taken up by, transported to,

and used by the body for energy production.

Maximum oxygen uptake, or VO2 max, represents the maximum volume of oxygen able to be

taken up by, transported to, and used by the body for energy production.

Oxygen uptake can be measured as either an Absolute value (L/min), or Relative (ml/kg/min).

Recap:

As exercise

intensity

increases, the

consumption of

oxygen

increases to

allow greater

levels of ATP

production.

Absolute VO2

(L/min)

Relative VO2

(ml/kg/min)

Oxygen uptake – absolute vs relativeTheory summary

The use of athlete’s relative VO2 allows us to compare aerobic performance.

Lebron James – 113 kg

3.7 km per match

Steph Curry – 86 kg3.9 km per match

Sources (left to right):WikiMedia CommonsFlickr

Factors affecting oxygen uptake

Body Size Age

Gender

Genetics Training

Oxygen uptake at restTheory summary

At rest, the demand for ATP energy is relatively small. As a result, parameters such as heart rate

and oxygen uptake remain at low levels.

Resting absolute oxygen consumption (VO2) for a 70 kg person is approximately 0.25 L/min.

Resting relative oxygen consumption (VO2) is approximately 3.5 ml/kg/min.

0 10 20 30

Time (secs)

VO2 @ rest

O2Demand

Source: https://www.youtube.com/watch?v=YKEOjWEzVGs

Theory summary

When exercise begins, oxygen uptake increases as the body attempts to meet the increased

oxygen demand. The increased oxygen demand results from the need to produce more energy for

ATP resynthesis.

Oxygen uptake at start of exercise

Sources (left to right):https://www.youtube.com/watch?v=GKXfpOZqREg

https://www.youtube.com/watch?v=lOAeTfI-Tlc&t=315s

https://www.youtube.com/watch?v=vHU9OFSwmEs

https://www.youtube.com/watch?v=cOK7DvZzo9g

Oxygen uptake at start of exercise

EventFemale Average

Speed for WR time (km/h)

400m 30.2

800m 25.4

1500m 23.5

Marathon 18.7

Theory summary

Oxygen deficit is the period of time at the start of exercise where the oxygen demand exceeds

the oxygen supply.

During oxygen deficit the body must obtain ATP from its anaerobic energy systems.

Oxygen deficit

10 20 30 40 50 60 70 80 90 100 110 120

Time (secs)

Oxygen Uptake Oxygen Deficit

Theory summary

Steady state is the state in which oxygen supply equals oxygen demand.

At these times, almost all of the required energy for ATP resynthesis is supplied aerobically.

Steady state

10 20 30 40 50 60 70 80 90 100 110 120

Time (secs)

Oxygen Uptake Oxygen Deficit

Applying these concepts

Source: 2014 VCAA Exam

Applying these concepts

Source: 2013 VCAA Exam

Theory summary

Aerobic steady state can only be reached once the body has made the required adjustments

(acute responses), to increase oxygen supply.

Important responses include:

• increased respiratory frequency;

• increased tidal volume;

• increased heart rate; and

• increased stroke volume.

Performing an aerobic warm-up will initiate a number of these responses prior to the event and

will reduce the time taken to reach steady state.

Also, chronic adaptations gained through aerobic training will improve an athlete’s aerobic

efficiency, and therefore increase oxygen supply faster.

Reducing time taken to steady state

Source: http://maxpixel.freegreatpicture.com/Stopwatch-Race-Time-Games-Treadmill-Sport-Jogging-259303

Theory summary

At the completion of exercise, oxygen consumption remains elevated, despite a reduction in the

demand for ATP energy. This elevated oxygen consumption (EPOC) is also referred to as Oxygen

Excess post-exercise oxygen consumption (EPOC)

30 40 50 60

Time (secs)

OxygenDemand

Source: https://www.youtube.com/watch?v=cOK7DvZzo9g

Theory summary

EPOC can be further divided into two parts: the first/fast replenishment part; and the

second/slow replenishment part.

Excess post-exercise oxygen consumption (EPOC)

-1 4 9 14 19

Recovery Time (mins)

Theory summary

The first 2-3 minutes of recovery is known as the fast replenishment part, and sees the highest

elevation in recovery oxygen consumption.

Recovery processes during the fast replenishment part of EPOC:

Fast replenishment

-1 4 9 14 19

ATP resynthesis

CP resynthesis

Restore oxygen to myoglobin

Theory summary

The remaining EPOC is known as the slow component. The recovery time in this part is

dependant on the usage and metabolic disturbances associated with the activity just

performed.

E.g. the higher the intensity and duration of exercise, the greater the accumulation of lactic acid,

and, therefore, the longer the slow replenishment part of EPOC will be.

Recovery processes during the slow replenishment part of EPOC:

Slow replenishment

-1 4 9 14 19

Return core temperature to

pre-exercise levels

Convert lactic acid to 𝑯𝟐𝑶 and

𝑪𝑶𝟐(oxidation of H+ ions)

Convert lactic acid

to glycogen,

protein and glucose

Restore heart rate and

ventilation to pre-exercise

levels

Restore other body systems to

pre-exercise levels

Multiple choice activityOn the graph below, the number 1 indicates the period when:

A. oxygen uptake is at resting levels.

B. oxygen supply equals oxygen demand.

C. oxygen supply does not equal oxygen demand.

D. post-exercise oxygen consumption is in excess of resting levels.

E. I don’t know, yet.

(2015 VCAA Exam Section 1 Q6)

Multiple choice – ResponseOn the graph below, the number 1 indicates the period when:

A. oxygen uptake is at resting levels.

B. oxygen supply equals oxygen demand.

C. oxygen supply does not equal oxygen demand. (82% correct)

D. post-exercise oxygen consumption is in excess of resting levels.

(2015 VCAA Exam Section 1 Q6)

Multiple choice activityWhich of the following strategies would not assist an athlete to reach a steady state faster

whilst competing in a 1500m track event?

A. Run at a faster early pace to reach steady state period

B. Complete an aerobic warm-up prior to the race

C. Complete 15+ weeks of aerobic training in the lead-up to the event

D. Attend a training camp in a hypoxic environment (altitude)

(Written by the author)

Multiple choice – ResponseWhich of the following strategies would not assist an athlete to reach a steady state faster

whilst competing in a 1500m track event?

A. Run at a faster early pace to reach steady state period

B. Complete an aerobic warm-up prior to the race

C. Complete 15+ weeks of aerobic training in the lead-up to the event

D. Attend a training camp in a hypoxic environment (altitude)

Multiple choice activityWhich of the following recovery processes is considered part of the fast component of an

athlete’s oxygen debt?

A. Oxidation of hydrogen ions

B. Restoration of oxygen to myoglobin

C. Return core-temperature to pre-exercise levels

D. Conversion of lactic acid to glycogen

Multiple choice – ResponseWhich of the following recovery processes is considered part of the fast component of an

athlete’s oxygen debt?

A. Oxidation of hydrogen ions

B. Restoration of oxygen to myoglobin

C. Return core-temperature to pre-exercise levels

D. Conversion of lactic acid to glycogen

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Presented by Chris Hudd - St Leonard's College · Maximum oxygen uptake, or VO 2 max, represents...

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