Exercise Physiology

• Ambient temperature 

  the temperature of the environment the athlete is performing in
• Core temperature


  the temperature inside the athletes body
• conduction


  heat exchanged by two objects in direct contact
• convection


  heat exchange by contact of fluid that is flowing
• radiation


  occurs when heat is transferred from a warmer body to cooler surrounding without physical contact
• evaporation


  the cooling of the body as a result of the vaporisation of sweat
• The body’s preferred mechanism of heat loss is dependent upon the following 3 factors

  • Environment
  • age
  • physiological state
• Environment factors

  • Ambient temperature
  • forced convection
  • barriers to convection
  • temperature radiating surfaces
  • relative humidity
• Age


  children don't sweat as much as their sweat gland are not as developed as adults
• physiological state

  • rate of heat production
  • hydration state
• Heart Rate


  the number of times the heat beats per minute
• Stroke Volume 


  the amount of blood pumped per heart beat
• Cardiac Output


  the amount of blood circulating around the body every minute

  HR X SV
• Double heat load


  a situation where the body is forced to deal with two forms of heat (metabolic heat and environmental heat)
• Cardiovascular drift 


  when heart rate increases to maintain cardiac output caused by a decrease in stroke volume
• Dehydration


  occurs when the amount of water leaving the body exceeds the amount being taken in
• drink 2L 24 hours before competition
• drink 600ml 3-4 hours before competition
• drink 400ml 1 hour before
• drink 200ml every 15 minutes
• drink x1.5 times the amount of water weight lost
• Heat Acclimatisation


  When heat tolerance improved by repeated exposure to hot environments
• How to heat acclimatise? How Long?

  •The first sessions of heat acclimatisation should last for 15-20 minutes and be combined with light to moderate activity

  •It should increase to 45-60min daily for approx. 8-9 days with an increase in exercise intensity & duration

  •5-10 days of living and training in the heat is recommended
• How to heat acclimatise? Where?

  •Athletes who are unable to use natural acclimatisation should use

  •Artificial heat sources, Climate chambers, Saunas, Sweat clothing
• How to heat acclimatise? When?

  •Should be completed 4-6 weeks before competition and then 2 times per week leading up to competition to maintain benefits
• Major Adaptations to Heat Acclimatisation

  • increase in blood plasma volume
  • increase sweat rate
  • start sweating at a lower core temperature
  • sweat becomes more diluted
• Cardiovascular Adaptation to Heat Acclimatisation

  •more efficient cooling mechanis

  •A lower core temperature

  •Reduces the body's need to send blood to the skin for cooling, resulting in a greater % of cardiac output going to the active muscles

  •Increased blood volume to allow for increased sweating
• Strategies to help cope with exercising in the heat

  • Hydration
  • Clothing
  • Pre-cool the body
  • Protection from the sun
  • Acclimatise
• Humidity

  Defined as the amount of water vapor that exists in the air
• Athletes seek advantage by manipulating

  • enhance training adaptation
  • improve performance
  • improve recovery
• Legal Performance Enhancer

  • protein enhancer
  • caffeine
  • creatine
• Illegal Performance Enhancer

  • anabolic steroids
  • EPO
  • blood doping
• Protein Powder Risks

  • increase risk of osteoporosis
  • colon cancer
  • kidney damage
  • increase water retention
• Protein Powder Benefits

  • increase muscle bulk
  • assists with recovery
• Caffeine Risks

  • headaches
  • increase heart rate
  • irritability
  • Insomnia
  • withdraw effects
• Caffeine Benefits for Athletes

  • Endurance events over 90 minutes
  • short duration high intensity
  • events requiring fast reaction time
• Creatine Risks

  • weight gain
  • cramping
  • diarrhoea
  • dehydration
  • dizziness
• Athletes Who Benefit With Creatine

  • short duration
  • high intensity
  • explosive power activities
• Anabolic steroids can be consumed by

  • orally
  • injected intramuscularly
  • taken as a gel
  • cream applied to the skin
• Physiological Benefits for Anabolic steroids

  • increase the performers size - strength and power
  • decrease recovery time
  • stimulates protein synthesis
  • improve rate of tissue repair