Chapter 13: Environmental Conditions And Performance

Question 1

• Describe the 4 ways heat is transferred into the environment.
• What body factors contribute to amount of sweat released?
• What’s hyponatremia?
• What’s hyperthermia?

Answer 1

1. Conduction: Transfer of heat with direct contact from on molecule to another, accounts for 3% of heat loss.
2. Radiation: Transfer of heat from a warmer body to surrounding indirectly, accounts for 60% of heat loss.
3. Convection: Radiated heat carried away from the body through air. Effective when air temp is lower than body temp, accounts for 12% of heat loss.
4. Evaporation: Result from sweating and is the main source of heat loss, accounts for 25% heat loss at rest and 80% during exercise.
   - N° of sweat glands, gender, body surface area and fitness.
   - Drinking too much water after sweating but only replacing water resulting in too little salt in the blood, which can interfere with the brain, heart and muscle function.
   - Overheating and extreme loss of salt and water through sweating.

Question 2

• Identify five physiological changes athletes would experience in very hot conditions.
• What are 3 reasons children have an increased risk of dehydration?
• What are 3 non-physiological factors that could put children at risk when their exercising in the heat?
• Identify and justify 3 strategies athletes could employ to aid them in performing under hot conditions.

Answer 2

• Increased HR, BP, sweating, core temp and breathing rate.
• Sweat less, get hotter and have more skin surface for their weight.
• Being distracted during opportunities to drink, not wanting to report symptoms and waits till thirsty.
  1. Hydration during event: replacement of fluid compensates for loss of fluid via sweat.
  2. Clothing: wear minimal clothing that is thin, light coloured and ventilation for increased skin exposure for evaporation and radiation.
  3. Heat acclimatisation: Training in hot conditions prior to comp prepares the body to perform in hear with adaptions being earlier onset of sweating and greater sweat rate.

Question 3

• How can dehydration increase in cold environments?
• Hypothermia increases in exercise in cold water, why?
• Physically what’s the main difference in pool and ocean swimmers?
• What are 5 physiological changes that can occur as a result of participating in cold water?
• What is shivering?

Answer 3

• Exposure to cold reduces the sensation of thirst.
• Radiation and convection increases to increase heat loss.
• Ocean swimmers have higher percentage of body fat as additional insulation to colder waters.
• Cold shock response, difficulty contracting muscles, lack of coordination through shivering, core temp decreases due convection increase as more blood is sent to muscles and After-drop.
• A body mechanism for producing heat by uncoordinated, rapid and involuntary contractions of the skeletal muscles

Question 4

• What are 4 dos and donts if an athlete is suffering hypothermia?
• How can wind affect performance?
• Explain wind chill
• What happens to partial pressure as altitude increases?
• How can a decrease in O2 at high altitude affect performance?

Answer 4

• Do: remove wet clothing, keep awake, wrap in blankets and share body heat. Dont: put them in a hot bath, apply direct heat, give alcohol and rub them.
• Cause difficulties in skill execution, battling extra resistance, affect timing and balance.
• Apparent temp due to air temp and wind speed. It works by the warmer body temp losing heat to the surrounding air, which is blown away and so loses more heat quicker.
• Decreases.
• Blood receives less O2, slowing glycogen metabolism and VO2 Max and energy decreases.

Question 5

• Give 5 long and short term responses on the body to high altitude.
• Why do athletes train at high altitude?
• How can athletes going to high altitudes be negatively affected?
• Athletes competing at high altitude can expect what 4 changes in the respiratory system.

Answer 5

• Short: increased HR, BR, BP, decreased VO2 max and O2 in blood. Long: Increased RBC volume, haemoglobin volume, capillarisation, decreased stroke volume and lactic acid tolerance.
• Increase RBC and haemoglobin concentration in blood due to low o2 concentrations to increase o2 delivery at sea level.
• Lose fitness as they can’t train their hardest.
• Increased BR, stimulation of chemoreceptors of low O2, blood alkalinity increases from increased gas exchange and arterial blood partial pressure decreases.

Question 6

• Athletes competing at altitude should adapt their training in what 3 ways?
• ‘Live high-train high’ is a technique to optimise beneficial effects of training at altitude. What are the pros and cons of this?
• Explain the technique of ‘Live high-train low’
• Explain the technique of ‘Live low-train high’
• What lifestyle changes need to be done while undergoing altitude training?
• Athletes who perform in hot weather will often observe that after they reach steady state, their heart rate begins to increase. What is the physiological reason for this to occur?

Answer 6

• Increase recovery, increase tapering period and reduced training loads.
• Pros: Max exposure to altitude for acclimatisation. Cons: expensive to travel, homesick, different food and mountain sickness, which can negatively affect training.
• Involves sleeping in a hypoxic tent that is attached to a generator pumping low-O2 air in to simulate high altitude conditions. The athlete can therefore sleep here to benefit from the adaptions of altitude while being able to maintain a higher training intensity at sea level.
• Involves using a simulated altitude training facility for training at sea level. Altitude (hypobaric) chambers manipulate the amount of available O2 to simulate different altitudes.
• Altitude increases basal metabolic rate (calories burnt at rest) yet reduce appetite so small frequent meals. Increase iron for RBC production.
• Stroke volume decreases.

Question 7

• Explain the benefits of four physiological adaptations the athlete would achieve after attending a altitude camp for three weeks?
• Records for 1km track cycling have all been made high up in altitude. The current record is 56.3 seconds. Why have these world records not been bettered at sea level?

Answer 7

1. Increased capillarisation: enhances transportation of blood and o2 to cells and muscles.
2. Increased RBC concentration: more RBC to carry o2
3. Increased Haemoglobin concentration: increases amount of o2 carried by blood.
4. Increased mitochondria: allows for higher intensity of aerobic respiration.
   - Air pressure decreases at altitude. Decreased air pressure means decreased drag created on athletes. So more drag is created at sea level than at altitude. Therefore with the same mechanical effort as at sea level will return faster times at altitude. 1km time trial is done by anaerobic athletes so the decreased oxygen concentration will not cause any negative affects on the athlete.