W9 - Hydration

Question 1

What is the difference b/w Dehydration and Rehydration?

Answer 1

• Dehydration: Process of loss
• Rehydration: Process of gain

Question 2

What is the difference b/w Euhydration, Hypo-hydration and Hyper-hydration?

Answer 2

• Neutral, low or high hydration status

Question 3

How much of the body is Total Water?

Answer 3

60% though varies

Question 4

How much is Intracellular; Extracellular - Interstitial & Intravascular

Answer 4

• Intracellular: 40% of body mass
• Extracellular:
• Interstitial: 15% of body mass
• Intravascular: 5% of body mass

Question 5

What are the 3 different types of dehydration?

Answer 5

Isotonic - equal loss of sodium and water; Hypertonic water loss > sodium loss → water shift from cells to extracellular fluid; Hypotonic - sodium loss > water loss - water shift from extracellular to cells

Question 6

Name 6 dehydration indices

Answer 6

Urine colour chart; Specific Gravity (well hydrated <1.010, sig dehydration 1.021-1.030); Urine osmolality (more accurage than Specific Gravity) meaurse no. of dissolved particles per m/l (700 mOsmol/ kgH2O); Salivery Osmolarity (sensitivity comparable to blood osmolality); Blood osmolality - represents blood tonicity, 2nd most accurate form of measurement (costly & requires trained personnel). 275 euhydrated, 300 dehydrated; Hydromety: Total Body Water Dilution - most accurate, but requires dilution of bodily fluids with deuterium oxide (oral)
• Plasma, saliva, or urine can be sampled, but loke blood costly & requires trained personnel

Question 7

Dehydration → ↓ CV capacity - how?

Answer 7

Reduced plasma volume; Decreased SkBF (blood flow); Reduced SV; Increased HR

Question 8

What are the 3 types of physiological strain associated with dehydration?

Answer 8

CV (↓ SV & CO, ↑ HR), thermal (↓ sweating, ↓ vasodilation) & renal. ↓ repeatability of movements & threhold for exhaustion.

Question 9

What pre-hydration strategies should you follow?

Answer 9

500ml night before, 500ml upon wakind and 400-600 before exercise

Question 10

Should you simply replace the fluid you’ve lost? If more, by how much?

Answer 10

More, 125-150%

Question 11

Water or sports drink?

Answer 11

ACSM - sports drink with 0.5-0.7g Na/L of fluid durig exercise >= 1hr

Question 12

What is a possible physiological impact of ice cold slurry or water ingestion?

Answer 12

Halted/ ↓ sweat response

Question 13

What are the benefits of hyperhydration?

Answer 13

• < change in core & skin temperature
• < onset for sweating •

Question 14

What are hydration recommendations?

Answer 14

• 2L of water prior to exercise can reduce Tcore increases
• Pairing with osmotic agents (sodium, glycerol, etc) can improve retention

Question 15

What benefit does sodium provide and in what cocentration?

Answer 15

• Increases plasma volume
• Increases time to exhaustion
• High concentration sodium drinks:• Volume of 110ml.kg
• Salt capsules: • 60mg.kg

Question 16

What benefit does glycerol provide and what is the suggested intake?

Answer 16

Like Sodium and can be used in conjunction - Enhances fluid retention
WADA Suggested intake:
• 1.22g.kg BM w/26ml.kg fluid per hour

Question 17

Is there a benefit in dousing and if so what is it?

Answer 17

• Ltd effect Tcore but • Sweat output (reduced water loss)
• Slowed dehydration
• Reduced changes in HR (↓ Cardiac Strain)