Basic physiology

1
Basic physiology

• Make it work for you!

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Performance

• Fitness
• VO2 Max
• Lactate threshold and tolerance
• Strength
• Weight lifting v. Badminton
• Technique
• Tennis v. marathon running
• Mental attitude
• Tiger Woods v. England rugby team!

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Basic physiology

• How does the body work during exercise?
• Heart and Lung
• Muscles
• Fuels
• Basis of fitness
• Heart and lung adaptation
• Muscle adaptation
• Metabolic and blood fitness
• Food

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What are muscles?

• Muscles are the contractile tissue of the body,
  and produce all movement, and circulation in the
  body.
• contain the contractile proteins actin and
  myosin.
• contain mitochondria and some fuel stores.
• are rich in arteries and veins to carry fuel and
  oxygen to the muscles and veins to carry waste
  products and carbon dioxide away.
• are the meat which we eat, and the red colour is
  due to another iron rich protein (myoglobin)
  which can store oxygen.
• contain a temporary store of energy in the form
  of creatine, and some fat and glycogen.

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How do muscles contract?

• When you want to move, electrical impulses come
  from the brain, down through the spinal cord and
  are transmitted through the motor nerves to the
  muscles.
• At the junction between the nerve end and the
  muscle, chemical signals are released from the
  nerve endings.
• Calcium to enter the muscle cell, and this enable
  the troponin proteins to move the myosin up the
  actin molecule.
• The causes the whole structure to shorten, and
  this contraction is the fundamental basis of all
  muscle contraction.
• To release the bond between actin and myosin
  needs energy, to shorten the muscle further or to
  relax the muscle.
• When the signal for contraction ends, the calcium
  is pumped back into the sarcoplasmic reticulum,
  and the muscle relaxes.

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How does the muscle get and use power?

• High energy phosphorous containing compounds,
  adenosine triphosphate (ATP).
• ADP is returned to ATP, from another high energy
  phosphorous source creatine phosphate, and from
  the energy factory of the muscle, the
  mitochondrion.
• Glucose in conditions of reduced oxygen
  availability, this is the source of energy in
  anaerobic exercise.
• A diet rich in creatine has the potential to
  increase the availability of creatine phosphate,
  which can increase high energy phosphate supply
  during intense exercise.
• Mitochondria can burn glucose, fats and ketones
  to make carbon dioxide and water if there is
  adequate supply of oxygen.

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Exercise types

• Anaerobic (lactate inhibited)
• Sprint running, speed climbing, sprint swimming.
• Mixed prolonged
• Football, Rugby, Squash, Dancing.
• Prolonged aerobic
• Long distance running, cycling.
• Intense aerobic, limited by later anaerobic
  lactate build-up
• Middle distance running, rowing, canoeing,
  cycling with hills/sprint finishes

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Aerobic exercise

• During the first few seconds of exercise, muscles
  use internal stores of high energy phosphate
  compounds (creatine phosphate) as the power
  source,
• Then burning glucose from muscle glycogen by the
  mitochondria.
• If oxygen is plentiful, this continues, but the
  fuel comes from other parts of the body, and can
  be glucose, fats or ketones to make energy.
  Typically, endurance sports are aerobic.
• Training measures which improve the supply of
  oxgen to muscles, and the function of
  mitochondria will improve the aerobic capacity,
  and thus the endurance of exercise.
• Prolonged aerobic exercise at low intensity is
  the best for weight control.
• Any antigravity exercise such as running or using
  a treadmill with an incline in a gym for 40
  minutes at a time will help burn fat.

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Anaerobic exercise

• Anaerobic exercise starts when there is not
  enough oxygen in the muscles, when the intensity
  of work increases.
• As a result, fats cannot be used for energy and
  glucose is not burnt completely, leaving behind a
  waste product called lactate.
• As tolerance of lactate is limited, anaerobic
  exercise is short. Sprint sports are anaerobic.
• Think back to when you last watched a 100-metre
  race. Often the sprinters breathe only once, or
  not at all. By the end of the race their muscles
  are very short of oxygen, are therefore working
  anaerobically and lactate is being formed.
• When lactate levels are too high, you will have
  to stop exercising, as you will feel very short
  of breath, perhaps even nauseous, and your heart
  rate will increase (generally above 140 beats per
  minute).

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• Training can increase both your capacity for
  aerobic exercise.
• Repeated bursts of anaerobic exercise can
  increase the ability to tolerate and metabolize
  lactate, and can therefore increase the intensity
  and duration of maximum work.

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Fuel source for exercise

• Glucose
• Free Fatty acids
• Ketones

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Time Course of Contributions from Different
Energy Sources
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Energy expenditure of different activities
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Understanding heart rate during training

• Calculate your maximum heart rate
• your age from 220 (e.g. for a 22 year old person
  it is 198 beats per minute).
• lt60 Maximum Heart Rate
• You are in the non-training zone.
• 60-70 Maximum Heart Rate
• You are training is in the aerobic zone, you will
  be able to do prolonged exercise. This is the
  zone to be in if you want to loose weight, but
  you will need to do prolonged and continuous
  exercise.
• 70-85 Maximum Heart Rate
• standard training zone. This is the zone to be in
  to increase your endurance and maximum oxygen
  consumption. It will also maximize your
  cardiovascular workout.
• gt85 Maximum Heart Rate.
• This is in the anaerobic zone you won't be able
  to do this for long. You should be doing bursts
  of this level of training to increase your
  lactate tolerance, and your high intensity work
  output.

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Heart rate and training
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Sports drinks

• Lucozade
• 15 grams of glucose per 100 ml, and no salts, is
  good for raising glucose quickly and replacing
  glucose when you want to reduce fluid intake
• Lucozade sports
• 6 grams of glucose per 100 ml, and has some salt,
  and is better for replacing fluids
• Powdered sports drinks
• made up to vary glucose and water content, to
  deal with each persons requirements,
• PSP22
• complex carbohydrate energy fuel for high-energy
  performance

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Better training and performance

• The key to better training is to identify what
  you are trying to get out of your exercise.
• Performance is the product of technique coupled
  with physical fitness, endurance and strength.
• Clearly individual practice and coaching will
  improve technique, and this will be specific to
  each individual sport.

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Increasing strength

• The bulk and strength of muscle groups are built
  through repeated rounds of effort, with
  increasing load.
• Typically weight training will increase muscle
  strength. Caution is required as there is a fine
  line between increasing load, and the potential
  for muscle and ligament strain.
• Strength training must be preceded and followed
  by stretching exercises, and advice sought from
  your coach or gym trainer.

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Increasing endurance

• If your sport or exercise is primarily aerobic
  such as running, cycling, rowing or distance
  swimming, you need to increase aerobic capacity
  (VO2max).
• Aerobic capacity is highest when young, and does
  decline with age, but studies of elders who
  regularly perform endurance sports such as cross
  country skiing show that any decline in VO2max
  can be limited.
• VO2max it can be increased by training. If you
  are physically unfit, you will soon exceed your
  aerobic capacity at low effort levels, and will
  start to exercise aerobically.
• To build your aerobic capacity, you need to do
  prolonged sub-maximal exercise. You will know
  that you are in this range because you can talk
  easily, and your heart rate will be less than 70
  maximum predicted for your age.
• Exercise at least every 2-3 days. And if you can
  do it daily, your fitness will improve rapidly.
• It doesnt matter what you do, running or cycling
  (either outside or on machines in the gym),
  rowing, or even quick walking will work.
• As you become fitter, you can then start to have
  periods within your exercise when you work harder
  and aim to raise your heart rate up to 70-80
  maximum predicted.

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Increasing intensity of effort

• Some sports require short periods of intense
  effort.
• Aerobic capacity is rapidly exceeded, and
  exercise is aerobic. Your lactate threshold is
  low.
• You will know that you are in this range because
  you will not be able to talk, and you heart rate
  is higher than 80 predicted maximum.
• If you are unfit, you will reach this level
  quickly, and to correct this you need to deal
  with your aerobic capacity.
• If you are fit, you will have a high lactate
  threshold.
• To improve the duration of high intensity
  exercise, you need to build your lactate
  tolerance.
• This is achieved by repeated and increasing short
  burst of maximum effort with short periods of
  rest between them.
• A typical example would be 1 minute of sprinting,
  with 2 minutes of rest repeated 10 times.

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Training for elite athletes

• If you are training to be an elite athlete, you
  will have the time and youth to combine all of
  the above into a tailored program.
• You will have endurance training, training to
  increase your lactate threshold and tolerance and
  gym work to increase strength.

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Training for the rest of us!

• You want to control or loose weight
• Morning exercise, before eating, staring with 10
  minutes of exercise which raises heat rate to
  70-80 maximum predicted, dropping down to lower
  effort level for a further 30 minutes at least
  with a heart rate 70 max predicted. Take water
  throughout exercise.
• You want to improve your endurance, and want to
  improve your heart and lung function
• Start at a lower level of effort, and taper up to
  70-80 maximum predicted, and finish with 5
  minutes of maximum effort. Drink either water or
  glucose containing drink throughout (lucozade
  sport).
• You want to improve muscle strength or change
  body shape
• Focused gym work with weights, or sit ups to deal
  with that belly.

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Fat burning

• If one of your goals is weight control, you want
  to augment the hormones which break down fat,
  growth hormone and glucagon.
• This takes about 20 minutes of exercise to become
  active, exercise to burn fat should be initially
  intensive, but then drop down to less intensive,
  but be maintained for at least a further 20
  minutes.
• It is helpful to perform any exercise at a time
  of day when these hormone levels are already
  high, and so exercise in the morning before will
  be more effective than in the evening to burn
  fat.
• It is important not to take food before exercise
  as this will reduce the fat burning by the
  muscles, which will use the energy from food
  ingested.
• Any post exercise meal should be in largely
  protein based and any carbohydrate taken as
  complex starches of low glycaemic index.