Article
Acute Hydration Score Overview
Benjamin T. House, Andy J. Galpin, Dan Garner, Vince Kreipke, and Thomas R. Wood

What Is the Acute Hydration Score?

Dehydration can negatively affect endurance, power, sport-specific tasks, and cognitive performance [1-3]. This score provides a window into hydration status over the previous 24 to 48-hour period. This score may reflect long-term hydration tendencies if that time period is representative of the individual’s normal daily routine with food, hydration, and exercise.

Keywords: Hydration, Electrolytes, Performance

Associated Biomarkers

Female Biomarkers Male Biomarkers
Serum Osmolality Serum Osmolality
Hematocrit Hematocrit
Hemoglobin Hemoglobin
Albumin Albumin

Experienced Physiological Effects:

  • Increased perceived exertion
  • Increased fatigue
  • Thirsty
  • Dizziness and lightheadedness, especially upon standing
  • Muscle cramping

Physiology Deep Dive:

Acute dehydration will increase plasma osmolarity and urine specific gravity [4-6]. As dehydration progresses, the blood can become more concentrated, resulting in increases in hemoglobin, hematocrit, and albumin [7-10]. The average athlete will lose around ~1L of fluid, 1.2 grams of sodium, ~200 mg of potassium, ~30 mg of calcium per hour of exercise [11-14], but there is a large degree of individual variability [15]. It is important to rehydrate appropriately through adequate fluid and electrolyte consumption, but not to induce hyper-hydration and hyponatremia through excessive intake of water [16, 17].

Constraint Zones:

Dark Green:

No acute dehydration signal is present; however, this does not indicate chronic hydration is ideal or optimal for one’s activity levels. Continue emphasizing hydration in and around training and daily life.

Green:

A mild acute dehydration signal is present. This is an acute signal, and with proper fluid and electrolyte intake, this can be remedied within a matter of hours. However, increased focus on proper rehydration practices may be warranted.

Yellow:

Acute dehydration may be present. This is an acute signal, and with proper fluid and electrolyte intake, this can be remedied within a matter of hours. However, increased focus on proper rehydration practices may be warranted.

Red:

Acute dehydration is likely. This is an acute signal, and with proper fluid and electrolyte intake, this can be remedied within a matter of hours. However, increased focus on proper rehydration practices may be warranted. Sweat testing to assess if this individual may be prone to excessive electrolyte losses may also be helpful.

References

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