Chapter 11: Hydration Flashcards
The water contained within a cell’s membrane, makes up approximately 2/3 of total body water.
Intracellular Fluid (ICF)
The water found outside of the body’s cells – ECF is found between cells and transported throughout the body via arteries, veins, and capillaries.
Extracellular Fluid (ECF)
What percentage of the total body mass is water?
50-70%
Describes the concentration of solutes in a liquid – various compartments hold fluids but the primary regulator of hydration status is the osmolality of ECF, specifically plasma osmolality. Multiple sites in the body house osmoreceptors that detect shifts in osmolality and generate responses to return the body to fluid and sodium homeostasis.
Osmolality
Physiological factors such as high osmolality or low blood pressure, which prompt sodium and water appetite.
Dipsogenic Signal
Specialized nerves that can sense change in pressure in the heart or blood vessels.
Baroreceptors
A solution with a lesser concentration of solute (i.e., fresh water compared to salt water).
Hypo-Osmotic
A key driver of thirst. If you are working with athletes who need to replace large volumes of sweat lost, consuming meals or snacks with sodium will promote a natural increase in fluid intake and also aid in retention of ingested fluids.
Plasma osmolality
Gastric Emptying Rate (GER)
The rate at which fluids and their contents pass through the stomach via the pyloric sphincter and into the small intestine – the faster and more complete the ___, the more quickly carbohydrates and electrolytes can be absorbed into the mesentery system, where they feed the liver first and then the rest of the body via the vascular system.
What are the 3 primary Involuntary actions that change the levels of fluid and electrolytes in the body?
Food & Beverage Intake, Urine loss during recovery, Sweat loss during exercise
What is the most significant influence-to-thirst for water?
ECF Osmolality
The movement or flow of air over an object.
Convection
A normal hydration status.
Euhydration
Translates to “as desired” and refers to eating or drinking as you are normally driven to (i.e., not purposely overeating or undereating).
Ad Libitum
What other factors, aside from hydration status, can contribute to heat illness?
Humidity, convection, heat, Clothing choice, Body composition, Training status, Level of exertion, Environmental conditions
A potentially serious medical condition in which the plasma sodium falls below 135 mmol/L, usually the result of fluid intake greatly exceeding sweat losses during prolonged exercise.
Exercise Associated Hyponatremia (EAH)
In most cases, calculating the average client’s sweat loss is not necessary. However, for those clients that require a level of coaching where it is required, which equation provided yields a client’s sweat loss volume kilograms?
Initial Weight (kg) – Post-exercise weight (kg) + fluid consumption during (kg) – Urine volume (kg)
There has been much discussion about the risk of Exercise-Associated Hyponatremia (EAH). Without diagnosing, what are some less severe symptoms that a client could exhibit who might be experiencing EAH often confused with severe dehydration?
Weakness, cramping, disorientation, vomiting, confusion
A measurement that represents the ratio of solutes in the urine versus distilled water.
Urine-Specific Gravity (USG)
Where is approximately 2/3 of body water found?
Intracellular fluid
What is the minimum percentage of beverage fluid replacement range that should be suggested for clients who lose more than 3% of their body mass during training and train more than once over a 24-hour period?
110-120%
A client completes three weight-training sessions with a Personal Trainer per week but also completes three, 1-hour group indoor cycle per week (not on the same day). They ask their Nutrition Coach for hydration advice. Which of the following responses would be most appropriate?
“Your workout sessions are not long enough in duration to cause sweat losses that dictate a personal hydration plan. Keep fluids available during exercise, and drink based on thirst.”
For clients engaged in prolonged endurance events who know what their sweat losses will be, which is the most appropriate advice to give in regards to developing a competition hydration strategy?
Do not drink in excess of sweat losses and limit body mass loss to < 3-4%.
What role does pickle juice play in regards to client hydration status?
Pickle juice contains a high concentration of sodium which can increase thirst drive and aid in consumed fluid retention.
