Long Term Effects of Exercise on the Body Systems

1. Long Term Effects of Exercise on the Body Systems Physiology of Fitness Andrew Roberts

2. Long Term Effects of Exercise on the Body Systems • What body systems do we mean? • Cardiovascular • Respiratory • Energy systems • Muscular • Skeletal • CREMS • As you exercise regularly your body adapts – you become fitter – more able to cope with the demands of exercise. We are going to look at what changes occur in the heart, lungs, muscle, skeleton and energy systems.

3. Learning Outcomes • Identify the 5 main body systems that are affected by long term exercise • Describe 3 key changes to the cardiovascular system after long term exercise (e.g. after 6 weeks) • Identify 2 changes to the energy systems as an adaptation to long term exercise • Examine and record our current level of cardiovascular fitness

4. Long Term Effects of Exercise on the Cardiovascular System What is the CV system? The heart and blood vessels of the circulatory system • Task • In pairs list what aspects of the cardiovascular system may change as a result of regular long term exercise? • In fours, compare results and see if you can add to your original list.

5. Heart • Cardiac Hypertrophy The heart increases in its size and blood volume. The wall of the left ventricle thickens ..why? to increase the strength potential of its contractions In sedentary, middle aged individuals it may be as high as 100 beats/min. Normal heart rate (HR) 60-80 beats / min Elite endurance athlete’s HR 28 – 40 bpm

6. CV system cont... • Increase in Stroke Volume SV = The amount of blood that can be pumped by the heart per beat. This means the heart can now pump more blood per minute. Why is this beneficial? Increased blood flow allows for faster and more efficient delivery oxygen and nutrients • In untrained individuals stroke volume at rest it averages 50-70ml/beat increasing up to 110-130ml/beat beat during intense, physical activity. • In elite athletes resting stroke volume averages 90-110ml/beat increasing to as much as 150-220ml/beat

7. CV system cont... Increased Cardiac Output (CO) SV X HR = CO As SV and HR increase during exercise CO will increase. In a trained heart both SV and HR have increased capacity. SV does increase to a point – however the significant increases in CO are caused by a bigger increases in 4200ml/min 15600ml/min heart rate 4800ml/min 36000ml/min

8. CV system cont... Discussion Eg An untrained student’s heart rate was measured at 140bpm while running 6mph on the treadmill After 6 weeks of exercise (running for 30 mins 3 times per week) I would expect HR to • Why? • What physiological changes would have occurred? decrease increase

9. CV system cont... • Decreased resting heart rate With regular training your resting HR falls. Also your HR returns to normal quicker after exercise. How could you measure these improvements over your 6 week program? • Capillarisation • Capillary networks increase to your cardiac and skeletal muscle. • This improves blood supply to the active muscles and improves the muscles’ efficiency

10. CV system cont... • Increase in Blood Volume • Your blood volume is the amount of blood circulating in your body • It increases as an adaptation to regular exercise • It increases as a result of capillarisation • Reduction in Resting Blood Pressure What are the 2 measurements of BP? • Systolic • Diastolic Research shows that the quicker your BP returns to normal the fitter you are. How could you measure this? Regular exercise can contribute to lowering BP.

11. CV system cont... • Decreased Recovery Time • HR recovery is a measure of how much your HR falls the first minute after exercise. • Fit people can recover more quickly. How? • The CV system has adapted and become more efficient through the demands of regular exercise • Increased Aerobic Fitness • This occurs as a result of what kind of training? • Aerobic training e.g.? • Running, cycling... • Aerobic fitness refers to endurance, or the ability to sustain work for prolonged periods. • How can you measure an improvement in aerobic fitness?

12. Recap TASK • In pairs, recall at least 3 key changes to your CV system as a result of long term exercise? • Cardiac hypertrophy • Increased SV • Increased CO • Decreased resting HR • Capillarisation • Increase in blood volume • Reduction in resting BP • Decreased recovery time • Increased aerobic fitness

13. Long Term Effects of Exercise on the Energy System Task • In pairs • Exercise can cover a wide range of meanings ....what exercise are we considering? On a flip chart write exercise in the middle and jot down what exercise means to you.

14. Long Term Effects of Exercise on the Energy Systems • Type Intensity Frequency Duration • What systems does our body use to supply energy to our muscles? • ATP-CP • Lactic Acid energy system • Aerobic Energy system 1-10 secs 10s – 2mins 2 mins +

15. Long Term Effects of Exercise on the Energy Systems • At cellular level muscles need what to contract? • What adaptations may occur at cellular level ? • Increase in level of enzymes for aerobic and anaerobic systems. • Increase in size of mitochondria. • Increased use of fat as an energy source • Fat combustion powers almost all exercise at 25% of aerobic power. • Fat oxidation increases if exercise extends to long periods as glycogen depletes • Trained athletes burn more fat as fuel than non-trained athletes. ATP

16. Long Term Effects of Exercise on the CV & Energy Systems Paired Task • Identify 2 changes to the energy systems as an adaptation to long term exercise • Describe 3 key changes to the CV system and how you may examine record those changes before and after a 6 week training program