Exercise in Environmental Extremes Flashcards
What are the area of concern?
Hyperthermia
Hypothermia
Lightening Storms
Over exposure to the sun
What are the concerns of Hyperthermia?
Has caused number of deaths
Athlete must be able to manage stress appropriately
Hyperthermia = increase in body temperature
Heat Stress concerns?
avoid overexposure in heat
athletes training in extreme conditions are at risk
Physiologically the body will continue to function if body temperature is maintained
body must dissipate heat to maintain homeostasis
How does heat dissipate from the body? 4 Mechanisms
Conduction (direct contact)
Convection (contact with cool air or water)
Radiation (heat generated from metabolism)
Evaporation (sweat evaporating from the skin)
Evaporative Heat Loss
Evaporation of water from sweat takes heat with it
When radiant heat and environmental heat are higher than body temp, evap is key
Lose 1 qt of water per hour for up to 2 hrs
Humidity impairs evaporation, 65% impairs, 75% stops evaporation
Monitoring Heat Index
Heat, sunshine, and humidity are monitored = combo of ambient temp + humidity
Wet bulb globe temperature index (WBGT) provides objective measure for determining precautions
WGBT
uses different thermometer readings
Dry bulb (standard mercury temperature) Wet bulb (thermometer with wet gauze that is swung around in air) Black bulb (black casing that measures radiant heat
DBT and WBT
measured with psychrometer (combo of thermometers)
wet bulb is lower
drier air = greater depression of wet bulb temp
Heat Illness
Heat Syncope (heat collapse) - rapid fatigue and overexposure
Caused by peripheral vasodilation or pooling of blood
Exertional Heat Cramps?
How to treat?
muscle spasms (calf, or abdominal) - caused by excessive water loss and electrolyte imbalance
treat with fluids and electrolytes and ice
Exertional Heat Exhaustion and how to treat?
result of inadequate fluid replacement
core temp of 102 and sweating and rapid discomfort
fluid replacement and cool environment
Exertional Heatstroke: symptoms and how to treat
life-threatening and needs emergency action plan
signs & symptoms - sudden onset of collapse, core temp of 104, shallow breathing, rapid pulse
Treatment: strip clothing, water, immerse in water, hospital quickly
Exertional Hyponatremia
fluid/electrolyte disorder (imbalance) - low sodium
Preventing Heat Illness
consume fluids and stay cool
continual re-hydration because only 50% of fluid is ever replaced
fluid should match sweat loss
Gradual Acclimazation
most effective to avoid heat stress
being accustomed to heat and exercising in heat
early pre-season training and graded intensity changes are recommended with progressive exposure over 7-10 day period
80% of acclimation can be achieved during 5-6 days with 2 hour morning and afternoon practice sessions
