Transcript Fitness and Training

FITNESS AND
TRAINING
B5
Katherine Castro & Pedro Pablo Talledo
Fitness
• Definition: Fitness is the state or condition of being fit;
suitability or appropriateness. Good health or physical
condition, especially as the result of exercise and proper
nutrition.
• Training can improve fitness, especially by improving the
pulmonary and cardiovascular function, but there may
also be some inherited elements to fitness, in particular
the distribution of fast and slow muscle fibers.
• http://www.brainpop.com/health/personalhealth/fitness/pre
view.weml#
Discuss speed and stamina as measures
of fitness
• Speed is the rate at which a movement is performed. The
time taken for a movement or series of movements must
be measured.
• For example, a swimmer might record the minimum
time taken to swim 50m.
• Stamina is the ability to continue an exercise for a long
time. The maximum duration of an exercise ifs measured
• for example, the maximum number of press-ups that
an athlete can perform.
Slow Muscle Fibers
• Slow muscle fibers have:
• an excellent blood supply with many blood capillaries. Because they contain
large amount of myoglobin, they appear red in colour.
• They have many mitochondria and so are rich in oxidative enzymes.
• Their aerobic capacity is large and because they do little or no anaerobic cell
respiration they have a very high stamina.
• Their strength is only moderate.
• Slow muscle fibres usually contain some glycogen, a polysaccharide that can be
use as a store of glucose, but they mostly rely on respiratory substrates supplied
by the blood system during exercise.
• Contract slowly but they keep going for a long time. Slow muscle fibers are good
for endurance activities long distance running or cycling.
Fast Muscle Fibers
• Fast muscle fibres have few mitochondria
• are rich in the enzymes of glycolysis and have moderate blood
supply.
• They contain little myoglobin so are pale in colour.
• They contract more rapidly than slow muscle fibers and have much
greater strength (exert more force per unit area). However, their
stamina is much less, because of the rapid accumulation of lactate
and the development of an oxygen debt during intense exercise
• Contract quickly but get rapidly tired
• Fast muscle fibers are good for rapid movements like jumping to get a
ball or sprinting.
• http://www.brainpop.com/search/search.weml?keyword=
muscle+fibers
B.5.4 Distinguish between the effects of
moderate-intensity and high-intensity
exercise on fast and slow muscle fibres.
• Fast fibers: can release large amounts of energy for a
short period of time by anaerobic respiration. This is good
for high-intensity exercise, for example 100m sprint races.
• Slow fibers: Release energy more slowly by aerobic cell
respiration, but can continue for longer, so are useful in
endurance events, for example marathons, moderateintensity exercise.
• Moderate-intensity exercise, such as long-distance
running or swimming, encourages the development of
slow fibers. High-intensity exercise, for example sprinting
or weight lifting, encourages the development of fast
muscle fibers.
Aerobic and anaerobic respiration video
• http://www.youtube.com/watch?v=PQMsJSme780
B.5.5 Discuss the ethics of using
performance-enhancing substances,
including anabolic steroids.
• Drugs can be used to enhance performance in sport, but
there are strong ethical arguments against their use.
• Drug-users gain an unfair advantage in competitions. For
example, in Men’s 100m finals in a recent Olympic
Games, a high proportion of athletes had probably been
taking anabolic steroids.
• Criminals profit from the sale of banned drugs. For
example there have been prosecutions of people who
have been making substantial profits from the illegal sale
of anabolic steroids. If athletes decided not to use these
anabolic steroids, these profits could not be made.
B.5.5 Discuss the ethics of using
performance-enhancing substances,
including anabolic steroids.
• Ethical arguments in favor of legalizing performance
enhancing substances
• Their use might overcome natural variation in physiology,
for example, variation in testosterone levels. If all athletes
were able to use them, competition might be fairer.
• If they do enhance performance, spectators might gain
more enjoyment from watching sports.
Effects of Steroids (not needed for IB)
• The long-term health of sportsmen and women who are
encouraged to take them may be damaged.
• For example anabolic steroids can cause men’s testes to
become smaller and sperm counts to be low. Because
anabolic steroids resemble testosterone, they can
interfere with women’s reproductive system and cause
abnormal menstrual cycles. High doses can cause liver
disease and there have been reports of athletes who take
anabolic steroids suffering from emotional problems, with
inappropriately aggressive outbursts.