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Hydration

Dehydration & Hyponatremia

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Dehydration

• What is dehydration?

• How can it be measured?

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Dehydration

• Dehydration = Loss of body weight

• How much loss is a problem?

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Dehydration = Loss of Body Weight

• 1% - Medical Definition of Dehydration

• 2% - 20% drop in Physical Performance

• 4% - Risk of Heat Exhaustion

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Dehydration Contributes to:

• Fatigue

• Decreased work capacity

• Lack of Endurance

• Poor recovery from Exercise

• Weight loss

• Depression

• Apathy

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Dehydration Contributes to (con’t)

• Lack of Cold Tolerance– Increased susceptibility to Hypothermia

• Lack of Heat Tolerance– Increased susceptibility to Heat Illness

• Discouragement

• Aggravates Shock

• Altitude Illness

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Dehydration contributes to (con’t)

• Heat Cramps – May play role in development of muscle

cramps

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Dehydration in Cold Environment

• Low humidity – greater moisture transport without as much

sweat.

• Cold Diuresis – One urinates more often

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Hyponatremia

• What is Hyponatremia?

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Hyponatremia

• Hyponatremia means low sodium concentration in the Blood.– Too little sodium– Too much fluid (water intoxication)– You can be dehydrated and Hyponatremic!

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Hyponatremia

• Sweat can contain as much as 90mEq/liter of Sodium

• Gatorade contains only 10mEq/liter

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Hyponatremia Prevention

• Are you Hungry or Thirsty?

• Eat salty foods - Junk food is good.

• Drink fluid to replace sweat loss - no more.

• People don’t eat when they are hot.

• People don’t eat when dehydrated and sick.

• Need 35mEq/liter Sodium to replace sweat.