1. SHORT & LONG TERM EFFECTS OF EXERCISE
Learning Objectives
To be able to explain the short term effects of exercise on the Muscular, Cardiovascular and Respiratory systems.
Content
1.4.1
Short-term effects of physical activity and sport on lactate accumulation, muscle fatigue, and the relevance of this to the player/performer
1.4.2
Short-term effects of physical activity and sport on heart rate, stroke volume and cardiac output, and the importance of this to the player/performer
1.4.3
Short-term effects of physical activity and sport on depth and rate of breathing, and the importance of this to the player/performer
1.4.4
How the respiratory and cardiovascular systems work together to allow participation in, and recovery from, physical activity and sport: oxygen intake into lungs; transfer to blood and transport to muscles; and removal of carbon dioxide
1.4.5
Long-term effects of exercise on the body systems (see 3.4.1–3.4.4)
1.4.6
Interpretation of graphical representations of heart rate, stroke volume and cardiac output values at rest and during exercise

2. Short term changes v Long term adaptations
You need to know about the short term effects of exercise and the long term adaptations resulting from training.
Short term effects are temporary changes that you experience when exercising, but they return to normal soon after exercise has stopped.
Long term adaptations require a lot of training and the changes last a lot longer (as long as training is maintained).

3. Short term effects – Muscular System
As soon as you exercise your muscular system experiences changes, mainly:
Increased demand for energy for muscles to work.
If we begin to move more than at rest, this will require additional energy.
Increased carbon dioxide production
When we release energy aerobically carbon dioxide is a by-product, along with water.
(Glucose + Oxygen  Carbon Dioxide + Water + Energy)
Increased temperature
Some of the energy produced is heat energy.
Lactic acid production
Lactic acid is a by-product when we produce energy anaerobically.
Lactate accumulation
If there is no oxygen to break lactic acid down, it is converted to lactate.
Muscle fatigue
A build up in lactate makes blood more acidic and inhibits muscle contractions.

4. Short term effects – Cardiovascular System
As the muscular system demands more energy, the cardiovascular system must also change to help with the supply by:
Increased heart rate
More beats per minute to increase the volume of blood (carrying oxygen) being pumped.
Increased stroke volume
Higher volume of blood being pumped per beat
Increased cardiac output
Increased volume of blood leaving the heart every minute (stroke volume x heart rate)
Increased blood pressure
Higher volume of blood leaving the heart results in more force against the artery walls.
Vascular shunting
Our body ensures more blood is pumped to the working muscles.
This enables more nutrients and oxygen to be delivered for energy production.
It does it by vasoconstriction of blood vessels towards less demanding areas of the body.
At the same time there is vasodilation of blood vessels going to the working muscles.

5. Short term effects – Cardiovascular System
What would be the cardiac output of for an individual with the following values for heart rate and stroke volume?
AT REST
DURING EXERCISE
Stroke volume (ml/beat)
68 ml/beat
120 ml/beat
Heart rate (bpm)
75 beats/minute
175 beats/minute
Cardiac output (L/min)

6. Short term effects – Cardiovascular System
What would be the cardiac output of for an individual with the following values for heart rate and stroke volume?
AT REST
DURING EXERCISE
Stroke volume (ml/beat)
68 ml/beat
120 ml/beat
Heart rate (bpm)
75 beats/minute
175 beats/minute
Cardiac output (L/min)
5.1 Litres/minute
21 Litres/minute

7. Short term effects – Respiratory System
The immediate changes to the respiratory system are:
Increased breathing rate
More breaths per minute to take in more oxygen and breath out carbon dioxide.
Increased depth of breathing
More air taken in each breath, containing oxygen that is delivered to working muscles.
Oxygen debt

8. Recovery Rates
A persons recovery rate is the time it takes for heart rate to return to resting level after exercise.
Immediately after exercise heart rate, and breathing rate remains higher than resting. T
This is to:
Continue taking in more oxygen.
Continue pumping higher volumes of oxygen rich blood to muscles.
Pay back oxygen debt.
Break down lactic acid.
Remove carbon dioxide via the blood and then the respiratory system.
Heart rate and breathing rate and heart rate can then return to resting levels.
The lower (faster) a persons recovery rate, the fitter they are!