Running hydration

The body has a mechanism to regulate temperature by sweat evaporation, this causes a loss of water.

This loss of water can be restored by fluid and/or food ingestion.

Hydration is “the process of providing an adequate amount of water to body tissues”¹.

By type

Main drink is water, with sports drink being water with added nutrients:

• carbohydrates
  • concentration of sugars in a drink
  • “The carbohydrate contributes to the performance enhancement by offsetting the depletion of the body’s stores of carbohydrate, the main fuel for intense endurance exercise”²
  • Typically <10% carbohydrates in a sport drink³
• electrolytes
  • “Any of the various ions (such as sodium or chloride) that regulate the electric charge on cells and the flow of water across their membranes."⁴
  • when sweating, we lose electrolytes, which can cause muscle cramping, fatigue, or high heart rate
    • “Loss of electrolytes, like sodium and potassium, can cause cramping. They’re expelled through perspiration (sweating)."⁵
    • “Your heart has to work harder when there’s less water in your blood”⁵
  • sodium
    • “The sodium in the drinks contributes either by accelerating the uptake of carbohydrate from the gut or by offsetting the reduction in circulating fluid volume that occurs through sweating or shift of fluid into active muscle”⁶
  • potassium

Depending on the concentrations of salt and sugar that the drink has, in relation to those in the human body, sports drinks can be categorized into:

Isotonic

• definition
  • Adjective isotonic* (of two solutions) having the same osmotic pressure
    • Noun osmotic pressure (physical chemistry) The hydrostatic pressure exerted by a solution across a semipermeable membrane from a pure solvent; the pressure needed to counteract osmosis.
• same (iso, similar) concentration of salt and sugar than the amount present in the human body.
• most popular type

Hypertonic

• higher concentration of salt and sugar than the amount present in the human body
• definition
  • hyper- (over) +‎ tonic
  • Adjective hypertonic* (of a solution) Having a greater osmotic pressure than another.

Hypotonic

• Adjective hypotonic* (of a solution) Having a lower osmotic pressure than another.
• lower concentration of salt and sugar than the amount present in the human body.

Summary

Brief compilation of the different types of sports drinks and what they are for⁷.

By time

Hydration can be done at three different moments of the exercise:

1. Before
2. During, or
3. After

Before running

Runners should be well hydrated before starting to run, euhydration having a normal level of hydration and avoiding hyperhydration or dehydration.

Dehydration impairs performance in most events, and athletes should be well hydrated before exercise

The concentration (osmolality, your electrolyte balance) of particles in urine should be normal.

Urine osmolality, specific gravity and colour may be markers that can be used as a guide (Shirreffs et al., 2004).

During run

• Dehydration should be limited to less than about 2% of body mass.
• If running for more than 2 hours: drink should include carbohydrates.
• If too much sweat (who lose more than 3g of sodium in sweat (Coyle, 2004).) and/or long runs:
  • Sodium should be included in the drink.
• Amount to drink
  • Don’t drink so much as to gain mass over the exercise.

After running

• For recovery, rehydration should include water and salts lost in sweat.

After exercise that has resulted in body mass loss due to sweat loss, water and sodium should be consumed in a quantity greater than those in the losses to optimise recovery of water and electrolyte balance (Shirreffs et al., 2004).

Post-exercise restoration of fluid balance after sweat-induced dehydration avoids the detrimental effects of a body water deficit on physiological function and subsequent exercise performance.

For effective restoration of fluid balance, the consumption of a volume of fluid in excess of the sweat loss and replacement of electrolyte, particularly sodium, losses are essential

Dehydration impairs performance in most events, and athletes should be well hydrated before exercise. Sufficient fluid should be consumed during exercise to limit dehydration to less than about 2% of body mass. During prolonged exercise the fluid should provide carbohydrate. Sodium should be included when sweat losses are high especially if exercise lasts more than about 2 hours. Athletes should not drink so much that they gain weight during exercise. During recovery from exercise, rehydration should include replacement of both water and salts lost in sweat.

Drink recipes

Recipes varies mostly in the amount of the following ingredients:

• water
  • mineral water
  • coconut water
• carbs
  • sugar
    • honey
    • white granulated sugar
• electrolytes
  • fresh lemon juice
    • calcium and potassium
    • balance the body’s pH
  • salt
    • sodium
    • “Table salt contains 2360 milligrams of sodium per teaspoon”⁸
  • pink himalayan sea salt
    • sodium
    • “contains less sodium per serving than ordinary table salt”⁹
    • Also has zinc, iron, calcium, potassium, magnesium.
  • Tomato juice
    • high in potassium

Electrolyte drink

Sports drinks are essentially a the combination of sugar, lemon, salt and water. The amount required should be adapted to each specific need based in the intensity, weather and expected effort.

Ingredients:

• water: 480ml water
• carbs: 4 tsp honey / white sugar
  • Most sports drinks are approximately isotonic, having between 4 and 5 heaped teaspoons of sugar per eight ounce (13 and 19 grams per 250ml) serving.¹⁰
• electrolytes:
  • 1/8 or 1/2 tsp sea salt / pink Himalayan sea salt
  • 1 large slice lemon or lime

References