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Flashcards in LEWIS: Oxygen Consumption Deck (60)
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1

Oxygen consumption is the

amount of oxygen used by the body to produce ATP

2

Begin to exercise we need more ATP and therefore use more oxygen so our

oxygen consumption increases

3

VO2 max is the

maximum amount of oxygen consumed and utilised by the body per minute

4

When the amount of oxygen consumed is lower than the amount actually required there is an

oxygen deficit

5

Oxygen deficit is when

insufficient oxygen is available at the start of exercise to provide all the ATP needed aerobically

6

Exercise = more oxygen consumed than at rest in order to supply mitochondria in muscle fibres so that they can manufacture ATP aerobically, if the level of exercise intensity increase, so does the level of oxygen uptake. This relationship continues, until during extreme exercise, we reach a level of

maximum oxygen consumption

7

Maximal oxygen consumption (VO2 max) is used to refer to the

maximum amount of oxygen that an individual can consume and utilise per minute during strenuous exercise

8

Oxygen consumption depends on many factors, such as:

fitness
weight
percentage body fat
gender

9

VO2 max is usually regarded as an accurate indication of the athlete's stamina as it estimates directly how much oxygen the athlete has available for

ATP resynthesis

10

VO2 max is linked to

OBLA/Lactate threshold

11

OBLA gives an indication of

endurance capacity

12

OBLA is expressed as a

percentage of VO2 max

13

Average untrained person will work at about what percentage of their VO2 max before OBLA occurs?

50-70%

14

Trained endurance performer will work at about what percentage of their VO2 max before OBLA occurs?

75-90%

15

Lactate is produced when hydrogen is removed from the

lactic acid molecule

16

OBLA is the

point at which lactate starts to rapidly accumulate in the blood

17

At rest lactic acid in the blood is

1-2mmol-1

18

During intense exercise the lactic acid in blood is

4mmol-1

19

If the level of exercise is submaximal the oxygen consumption reaches a

steady state

20

steady state is the period of exercise when oxygen consumption matches

the amount needed by the body to produce the ATP required for that level of exercise

21

Oxygen consumption is measured by subtracting the volume of oxygen expired during a period of time from the

volume of oxygen inspired during the same time period

22

A direct method of VO2 max measurement is:

Treadmill run/cycle ergometer workload is increased every 2-3 minutes
-Oxygen consumption will rise during each stage
-Runner unable to continue owing to exhaustion = reached their aerobic capacity
-Amount of oxygen being consumed in these final few seconds of exercise is then measured to give a VO2 max value

23

Factors affecting VO2 max:

GENDER
AGE
LIFESTYLE
TRAINING
BODY COMPOSITION
GENETICS

24

Gender affects VO2 max:

-Male bigger (70mlkg-1min-1) than female [20% lower VO2 max] (60mlkg-1min-1)

25

VO2 max is lower in females than males, as females have a:

-Smaller left ventricle, smaller stroke volume
-Lower maximum cardiac output
-Lower blood volume, resulting in lower haemoglobin levels
-Lower tidal and ventilatory volumes

26

Age affects VO2 max as:

-max HR drops (5-7 bpm per decade)
-increase in peripheral resistance results in a decrease in maximal stroke volume
-blood pressure increases both at rest and during exercise
-Less air is exchanged in the lungs due to a decline in vital capacity and an increase in residual air

27

Lifestyle affects VO2 max due to

-smoking
-sedentary lifestyle
-poor diet
-body fat percentage

28

VO2 max can be improved by up to what percentage following a period of aerobic training (continuous, fartlek, aerobic interval)

10-20%

29

19 physiological adaptations following aerobic training, which improve VO2 max, are:

1-increased max cardiac output
2-increased stroke volume/ejection fraction/cardiac hypertrophy
3-greater HR range
4-less oxygen being used for heart muscles, more available for other muscles
5-increased A-VO2 diff
6-increased blood volume and haemoglobin count
7-increased glycogen and triglyceride stores
8-increased myoglobin content
9-increased capilliarisation (lungs and muscles)
10-increased number and size of mitochondria
11-increased concentrations of oxidative enzyme
12-increased lactate tolerance
13-reduced body fat
14-slow twitch hypertrophy
15-increased venous return
16-bradycardia (reduction in resting HR)
17-decrease in lactic acid accumulation
18-increased enzyme efficiency
19-improved transfer of oxygen to mitochondria via myoglobin

30

Body fat percentage/composition affects VO2 max as:

VO2 max decreases as body fat percentage increases