THE PHYSIOLOGY OF FITNESS

The long-term effects of exercise of the body’s systems

Part Two: Respiratory System

Session Outcomes

1. Describe two respiratory adaptations through long-term exercise programmes.(P3)

2. Record respiratory responses to 2 types of exercise(P3)

3. Explain 2 respiratory adaptations that will occur through long-term training in an activity of your choice.(M2)

In pairs, no. 1 is to ask no.2 how to achieve each of these outcomes.

Next, no. 1 is to assess these plans. Next , no. 2 is to plan how to achieve the outcomes.

No. 1 to assess. Compare your plans and decide on the best ideas.

Long-term effects of exercise on the respiratory system

The muscles demand more oxygen and as a result more CO2 is produced. To combat this the body adapts by:

Increasing strength of respiratory muscles

Increasing vital capacity Increasing oxygen diffusion

rate Increasing minute

ventilation

1. Increased strength of the respiratory muscles

The diaphragm and intercostal muscles increase in strength.

This allows for greater expansion of the thoracic (chest) cavity.

More expansion provides more efficient inhalation and expiration

2. Increased vital capacity

Vital Capacity (VC) is the maximal volume of air that can be expired after maximal inspiration in one breath

Mainly down to the increased strength of intercostal muscles

http://www.youtube.com/watch?v=G3pfeXULyv0

Measuring Vital Capacity with the Balloon Method

Stretch a round balloon several times to relax the material and make it easier to inflate.

To measure vital capacity, inhale as much air as you can and exhale forcefully into the balloon. Pinch the end of the balloon and measure its diameter (see Figure 1, to right).

Record the result in your assessment notebook.

Figure 1. Measuring the diameter of the balloon, in centimetres (Muskopf, 2003).

Conversion into Lung Volumes

These can be used as a benchmark with performers to see if vital capacity is increasing through exercise.

Figure 2. Use this graph to find the balloon volume (in cubic centimeters) for a given balloon diameter (in centimeters) (Muskopf, 2003).

Measuring Vital Capacity with the Balloon Method

3. Increased oxygen diffusion rate

Increase in the number and size of capillaries leads to more efficient diffusion:

More O2 from capillaries to tissues.

More CO2 from cells to the blood.

Regular training leads to better transportation of O2/CO2 therefore an increase in oxygen diffusion rate

4. Increased minute ventilation Minute ventilation

(minute volume) is the amount of air inspired or expired in one minute.

It is dependent on breathing rate and total volume

It’s expressed as: VE = volume of air

expired in a minute VI = volume of air

inspired in a minute During exercise

adults can generally achieve 15 times resting values

Session Outcomes

Describe two respiratory adaptations through long-term exercise programmes.

Explain 1 respiratory adaptation that will occur through long-term training in an activity of your choice.

Respiratory Adaptations to Training Pulmonary ventilation increases during maximal effort after training;

you can improve performance by training the inspiratory muscles. Pulmonary diffusion increases at maximal work rates. The a-VO2 diff increases with training due to more oxygen being

extracted by tissues. The respiratory system is seldom a limiter of endurance performance. All the major adaptations of the respiratory system to training are

most apparent during maximal exercise. Although the largest part of the increase in VO2max results from the

increases in cardiac output and muscle blood flow, the increase in a-VO2 diff also plays a key role. This increase in a-VO2 diff is due to a more effective distribution of arterial blood away from inactive tissue to the active tissue, so that more of the blood coming back to the right atrium has gone through active muscle.