3.1.1 – The demands of performance – aerobic and anaerobic exerciseLearning objectives

To describe the difference between aerobic and anaerobic respiration.

To understand the functions of the circulatory system.

To be able to define heart rate and describe the effect training has on resting H.R.

To describe the components of blood and the role they play in the body.

To be able to describe the long term effects of training on the circulatory system

Breathing action and the gases that exchange are vital to sportspeople.

At rest, we take about 15 breathes per minute. This is called tidal volume.

Exercise and breathing

Tidal volume definition: is the amount you breathe in and out in one normalbreath.

During and after extreme exercise this tidal volume can increase dramatically.

Aerobic exercise can be maintained for long periods and includes activities like walking, jogging, cycling and swimming.

There are two different types of respiration.

Aerobic respiration:

glucose + oxygen energycarbon dioxide+ + water

Aerobic respiration

When you exercise at a high intensity, the cardiovascular system cannot supply enough oxygen to the muscles.

Anaerobic respiration:

With no oxygen available, glucose is used BUT produces energy & lactic acid. (This causes fatigue)

Activities like sprinting, weightlifting, jumping and throwing are anaerobic in nature

glucose energy + lactic acid

Anaerobic respiration

Which respiration system do you think the follow sportspeople mainly use?

The circulatory system has three functions:

1. Transporting substances around the body. These include oxygen, glucose, carbon dioxide and waste products.

3. Protecting the body. Blood contains cells and anti-bodies that fight infection and stop bleeding

2. Controlling body temperature.

Red blood cells carry oxygen from the lungs to the muscles + Removes CO2 from muscles to lungs.

Contain a red-coloured compound called haemoglobin which bonds with oxygen to form oxyhaemoglobin

How important do you think red blood cells are to sports performance?

The Components of Blood

White blood cells defend against disease.

Platelets clot the blood to stop bleeding.

They are vital to health and preventing infection after injury.

Platelets are important in healing injuries.

Each individual has a maximum heart rate –

- maximum heart rate can be calculated below

Maximum Heart Rate (MHR) = 220 – age

So, a 25 year-old would have a maximum heart rate of

- 220 – 25 = 195 bpm

The heart during exercise

To keep the body supplied with what it needs, the heart beats faster and with greater force.

This means that the heart rate and stroke volume increase.

What do you think happens to the cardiac output?

Immediate effects of exercise on the circulatory system

Blood is moved from where it is needed least to where the action is. (eg. away from organs to working muscles).Blood vessels widen and narrow at different points.

The exercise generates heat so blood moves to the skin. This causes the skin to go red and sweat which cools you by evaporation.

Immediate effects of exercise on the circulatory system

Regular exercise causes the following changes to the heart.

1. The heart gets larger

2. The muscular wall become thicker and stronger

3. Stroke volume at rest increases, leading to a lower resting heart rate.

4. Increased VO2 max

5. Recover form exercise quicker

Long term effects of training on the circulatory system

Monitoring heart rate

What is your resting heart rate?

What is heart rate?

“The number of beats per minute”

Find your pulse in your neck (carotid pulse) or on your wrist (radial pulse).

Count for 15 seconds x 4 = ____ Beats per minute

The lower your resting heart rate the fitter you are. Why?

The cardiac muscle in a trained athlete is larger and stronger. Each beat forces out a larger amount of blood than a normal heart. It therefore takes less beats in a minute to supply the body with enough oxygen.

42 bpm 38-40 bpm 34 bpm

Monitoring heart rateHeart rate increases and decreases with the stress and demands of exercise. Heart rate can tell us a number of things about the exercise we are doing.

Monitoring heart rate

Monitoring heart rate in a training sessions can tell you if it too hard or too easy.

How quick pulse rate return to resting is a measure of

fitness.

Linked with the principle of overload.

Ensures the intensity is correct.

Performers can work within their ‘target training zone’ and therefore get the

most improvements.

Oxygen debt

Oxygen debt – “the amount of oxygen needed after exercise to return its normal state”.

The oxygen reacts with the lactic acid to form CO2 and water.

Rapid and deep breathing is needed for a short period after high intensity exercise (ANAEROBIC) in order to repay the debt.

The recovery processRecovery allows for muscles to become stronger and improves the lactic threshold. Eating carbohydrates after exercise will replenish energy stores and help recovery of damaged tissues.

The recovery phase:-Must be planned into an exercise session-Should improve fitness levels-Repair damaged tissues

Summary Questions:

Describe the aerobic respiration equation.

What is oxygen debt?

What does heart rate tell you about the exercise intensity?

How do you calculate maximum heart rate?

What are the 3 functions of the circulatory system?

What do red blood cells, white blood cells and platelets do within the body?