A2 Physical Education

Health Components of Physical Fitness: Aerobic Capacity

The ability to take in, transport and use oxygen to sustain prolonged periods of

aerobic/sub-maximal work.

Aerobic Capacity

Aerobic capacity is dependant upon the efficiency of: Pulmonary ventilation and external respiration (take in O2) Internal transport via the heart, blood and blood vessels (transport

O2) Muscle cells to use 02 for energy production (use 02)

The higher the VO2max, the greater the potential the athlete as to work at a high percentage of VO2max (just below anaerobic endurance), thereby increasing their work intensity and delaying fatigue.

This is why many athletes have this ability as a main training objective within their periodised training programme.

V02 max

The highest rate of oxygen consumption attainable during maximal exhaustive

work

A typical male of Wiggins's age who does not do much training would be likely to have a VO2max between 35 and 45.

Wiggins is likely to have a value above 70, possibly even as high as 80.

A person's endurance potential can be measured by taking a VO2max reading, which shows how

much oxygen is used per minute for every kilogram of body weight (ml/kg/min)

Factors affecting VO2max

Physiological make-up Heredity/ Genetics

Aerobic TrainingGender

Measurement: Physical Work Capacity Test (PWC 170)

o A sub-maximal test on a cycle ergometer.

o Performer cycles at 3 progressive low-to-moderate work intensities and their HR values are recorded.

o As HR increases linearly with work intensity, a line can be drawn through these points on graph, which can be extended to predict the intensity level that they would be working at when their heart reaches 170bpm.

o This figure is chosen as an approximate anaerobic close to maximal, level of work based on the assumption that VO2max is closely linked to maximal HR.

A progressive and maximal 20 metre shuttle run test.Timed by a bleep which becomes shorter until the athlete cannot

keep up or drops out.This provides a level and shuttle number score which is then

compared with standardised tables to estimate/predict a VO2max value.

Measurement: Multi-stage Fitness Test (MSFT)

VO2max normative data

Critical Threshold = Resting HR + % (max HR – resting HR)E.g60% HR for a 17 year-old with a resting HR of 72bpm

Critical threshold = 72 + (0.6 x 131) = 151 bpm

Critical threshold

Using this formula work out your own critical thresholds and use this to plot a graph showing

your own ‘training zone’

Anaerobic threshold zone: 85-100%

Target heart rate zone: 65-85%

Fat burning zone: 50-65%

Recovery zone 50% or less

My personal ‘training zones’

60

125

170

145

190H

eart

Rat

e (b

pm)

Percentage of maximum

HR

Percentage of VO2max

Training objectives

50 28

60 42 Fat burning / re-energise glycogen stores

70 56 Develop oxygen transportation systems

80 70 Improve lactic acid threshold

90 83 Speed

100 100

Approximate VO2max percentages

F• Frequency

• Minimum of 3-5 times per week for a minimum of 12 weeks

I • Intensity• Measured using HR % within the

critical threshold / training zone

T •Time•Minimum 3-5 mins to 40+ mins

T •Type•Overloading the aerobic energy systems

Aerobic Training•Aerobic training involves whole body activities like running, cycling, rowing & swimming.•The aim is to overload the cardio-vascular & respiratory systems to increase aerobic capacity / VO2max

•Continuous running

•Repetition running

•Interval Training

•Fartlek training

Aerobic Training Methods

Aerobic work is fuelled from glycogen/glucose and free fatty acids (FFA’s). This is dependant upon:

The duration & intensity of the aerobic training The availability of glycogen and FFA’s.

Energy system & food fuels during aerobic work

Glycogen is the major fuel for the first 20-40 mins of exercise

After about 20-45 mins there is a greater breakdown of fats alongside glycogen as the energy fuel

After 20-45 mins glycogen stores start to deplete and there is a greater mix of glycogen and fats to fuel aerobic work

When glycogen stores become almost fully depleted after about 2hrs, FFA’s have to be used for aerobic energy production

If exercise intensity is too high then OBLA is reached and glycogen has to be broken down to anaerobically to continue resynthesising ATP