Transcript Effects of exercise - Pearson Publishing

Effects of exercise
© 2006 Pearson Publishing Tel 01223 350555
Effects of training
Aerobic activity leads to increased:
• Aerobic threshold
• Cardiovascular endurance
• Lung capacity
Anaerobic activity leads to increased:
• Anaerobic threshold
• Muscular endurance
• Lactic acid tolerance
Cardiovascular fitness
• It is very important to remember that cardiovascular
fitness is not just for top sportspeople
• It is the most important aspect of fitness for all of
us because it involves the circulatory and the
respiratory systems
• The heart or cardiac muscle is different to any other
muscle in that it never tires. It must continually
pump blood — without it, we would die. If the blood
vessels become blocked or hardened, angina or
heart attack occurs
• Improved cardiovascular fitness increases the
number of blood vessels in and around the heart, so
reducing the risk of a heart attack
Body changes during exercise
• Cell respiration in the muscles and the level of
carbon dioxide in the blood increase
• The brain detects this and sends a signal to the
lungs to breathe faster and deeper
• Gas exchange in the lungs speeds up
• More carbon dioxide passes out of the blood and
more oxygen passes into it
• The brain also sends a signal to the heart to beat
faster, making the heart rate go up
• The muscles squeeze on veins, sending more blood
back to the heart — this helps the stroke volume
(SV) to increase
Body changes during exercise
• Cardiac output rises — more blood gets pumped to
the muscles each minute
• This means more oxygen reaches the muscles each
minute and more carbon dioxide is carried away
• Arterioles widen so that your blood pressure won’t
get too high
• Blood gets moved to where it is needed from where
it is less needed, eg from your gut to your legs
• To make this happen, blood vessels widen
and constrict at different points (vasodilation
and vasoconstriction)
Body changes during exercise
• Exercise generates heat,
making the body hotter
• Blood is directed close to
the skin to cool down
• This makes the skin redden
• The body is also cooled by
sweating, through evaporation
• Blood flow to skeletal
muscles increases
• Movement at joints may
increase markedly
Short-term benefits of exercise
• Healthier heart, muscles,
bones and joints
• More calories burnt
• Increased energy levels
• Reduced stress, depression
and anxiety
• Better sleep
• Faster, sharper thinking
Cardio-respiratory training
Effects of this type of training include:
• The heart becomes more efficient
• The stroke volume is increased and, as a result, the
resting heart rate becomes lower
• Recovery after exercise becomes quicker
• Blood volume, red cells and haemoglobin increase
• Arteries grow larger
• The diaphragm grows stronger
• The lungs become more expandable, increasing
in volume
Effects on circulatory system
• Increase in blood volume — more blood in the body
means more haemoglobin and, therefore, more
oxygen when it is needed, eg during exercise. So
there is greater endurance
• Heart muscle gets bigger and stronger — with each
beat, or stroke, the heart will pump out more
blood. The heart rate of a fit person will be lower
than an unfit person and the heart will pump out
greater quantities of blood (increased stroke
volume). Therefore, whatever the level of exercise,
and whatever the body’s oxygen requirement, the
fit person will need fewer beats of the heart to
meet the requirement than an unfit person
Effects on circulatory system
• Lung capacity increases — more oxygen can
be breathed in when needed and more carbon
dioxide can be breathed out
• The heart’s workload is reduced — if the heart
does not need to beat as often, it will probably
last longer which could mean a longer life
• Less chance of heart disease — harmful cholesterol
is less likely to build up in the coronary arteries of a
fit person than in an unfit person. Cholesterol in the
coronary arteries can cause fatal heart attacks
Effects on circulatory system
• Increase in capillary network so more efficient gas
exchange — regular exercise results in an increase in
the number of capillaries between each artery and
vein. This means more efficient exchange through
the capillary walls of oxygen for carbon dioxide and
muscle fuel for waste products, ie tissue respiration
becomes more efficient
• Blood supply to the heart increases — this is due to
the increased number of capillaries around the
heart muscle. This makes the heart stronger and
more efficient
Effects of regular training
• Promotes bone strength and thickness — a physically
fit person will have stronger and slightly thicker
bones than an unfit person. This means the fit
person will be more resistant to breaks and will be
able to take much harder blows
• Keeps weight down —
but only with a
sensible diet
Effects of regular training
• Performance in sport will improve — this is due to
an improved aerobic base (a person’s basic level of
aerobic fitness). If a person has basic fitness, they
will perform better in sport. For example, a
footballer may have superb ball skills, but if he
is unfit he will not be able to use them in a
competitive match
• Less fatigue means less injury — many injuries in
sport occur towards the end of the game when a
player is fatigued. Therefore, the fitter the player,
the less likely they will be to suffer injuries
Benefits of strength training
Benefits of strength training include increased:
• Muscle mass and strength
• Bone density
• Metabolism
• Overall stability and balance
Weight loss
• Exercising for 30 minutes a day can help weight loss
• Reducing your weight by just ten lbs (4 kg) may be
enough to lower blood pressure
• Losing weight can help to
enhance the effects of high
blood pressure medication
• It may also reduce the risk
of other conditions, such
as diabetes, heart attack,
breast cancer, obesity, high
blood cholesterol and stroke
General benefits of exercise
• Improved health
• Stronger muscles
• Better flexibility
• Improved posture
• Improved heart and lung system
• Better appetite
• Feeling more relaxed
• Better social life
• Improved quality of life
• Reduced risk of disease and ill-health