15.3 – Environmental Factors and Training

Question 1

Heat exchange mechanisms

Answer 1

• The hypothalamus controls body temperature by detecting signals from the skin and blood, helping maintain temperature by releasing heat into the environment.
• Cold weather: The body can lose too much heat, lowering core temperature.
• Hot conditions: The body can overheat, causing organs to stop working.

The body cools itself through four methods:
1. Radiation: Heat leaves the body into a cooler environment.
2. Conduction: Heat transfers through liquids, solids, or gases (e.g., using cool water).
3. Convection: Air moving around the body helps cool it (e.g., using a fan).
4. Evaporation: Sweat evaporates from the skin to cool the body.

• Evaporation is the most effective cooling method.
• In humid conditions, sweat can’t evaporate well, leading to dehydration and overheating.

Question 2

Impact of Equipment and Clothing in Training

Answer 2

• Clothing and equipment can impact temperature regulation during training.
• In hot conditions:
  
  • Heavy gear can block cooling and prevent sweat evaporation.
  • Loose, breathable, and lighter-colored clothing helps keep the body cool.
• In cold weather:
  
  • Layering is key:
    
    1. First layer: Wicks moisture away from the skin.
    2. Middle layer: Provides insulation.
    3. Outer layer: Protects against wind and water.
  • Layering allows athletes to adjust their clothing as needed for comfort and temperature control.

Question 3

Atmospheric Pressure and Altitude

Answer 3

• At higher altitudes, barometric pressure decreases, resulting in less oxygen in the air and blood.
• This leads to reduced exercise performance, especially in endurance events.
  
  • Example: At 2,000 meters above sea level, hemoglobin retains only 90% of the oxygen it would at sea level, impacting endurance athletes.
  • No world records for running distances over 800 meters have been set at high altitudes.
• Sprinting and jumping athletes tend to perform better at higher altitudes due to:
  
  • Reduced air pressure and resistance.
  • These events rely more on anaerobic energy.

Question 4

Altitude Acclimatization

Answer 4

• Altitude Training Debate:
  
  • Training at high altitudes may increase oxygen-carrying capacity, but the benefits for sea-level performance are unclear.
• Physiological Adaptations:
  
  • At high altitudes, the body:
    
    • Increases breathing rate.
    • Produces more red blood cells and hemoglobin to improve oxygen delivery to muscles.
• Training Limitations:
  
  • Reduced oxygen at high altitudes makes intense training harder, which can negatively impact power and endurance.
• “Live High, Train Low”:
  
  • Many athletes use this strategy:
    
    • Live at high altitude for adaptation.
    • Train at sea level for better performance.
• Acclimatization:
  
  • Endurance athletes typically acclimatize for 2-3 weeks before competing in high-altitude events.

Question 5

Air pollution

Answer 5

• Air Pollution:
  
  • Exercising in areas with high air pollution (e.g., lead, ozone, nitrogen dioxide) increases health risks.
  • Active individuals inhale more pollutants than sedentary people.
  • People with asthma, heart, and lung issues are especially vulnerable.
• To reduce risks, the Canadian Lung Association recommends:
  
  • Exercise in cooler weather, avoiding peak summer pollution.
  • Avoid high-traffic times and afternoon hours when ozone levels are highest.
  • Check air quality indexes before exercising outdoors.
  • Consider indoor exercise on “bad air days.”
• Breathing in pollutants can lead to:
  
  • Breathing issues.
  • Chest pain.
  • Coughing.
  • Worsening conditions like asthma, emphysema, and heart disease.