W6-L2: Hydration for Sports Performance Flashcards
How does thermoregulation play a role during exercise?
- Exercise increases metabolic heat due to muscle contractions, small amounts lost through the skin, but most is transferred to the core
- Thermoreceptors (Brain & Skin) detect the rise in body temperature, hypothalamus responds by increasing blood flow to the skin, initiating sweating
- Sweating and Heat Loss: Vasodilation increases blood flow to the skin, aiding in heat transfer from core to skin by evaporation – the primary cooling mechanism during exercise
How does Exercise Training affect Thermoreg.?
Exercise Training Improves Thermoregulation:
- Trained individuals sweat more efficiently and can regulate temperature better during exercise.
- Training leads to earlier sweating, increased sweat rate, and improved cardiovascular efficiency.
How is Hyphohydration induced by exercise?
How does the body regulate body fluids?
How does ~2% MILD DEHYDRATION
affect performance?
- ↑ fatigue and rate of perceived exertion
- impair attention and psychomotor skills
- impair immediate memory skills
- impair neuromuscular control
- ↓ accuracy, power, and strength
- ↓ muscular endurance
- ↓ motivation
- ↓ sprint performance
How does >3-4% MORE SEVERE DEHYDRATION
affect performance?
- ↓ sweat rate and evaporative heat loss
- ↓ blood volume
- ↓ blood pressure
- ↑ in core body temperature
- cardiovascular strain
- altered metabolic and central nervous system functioning
How can individuals minimize hydration?
- Assess hydration status and start exercise hydrated
- Hydrate to maintain body mass losses within 2-3%
- What to drink?
- Calculate sweat rate
- Rehydrate after exercise
What is an Osmometer?
How can we assess hydration status?
- No perfect measurement for all situations
- Plasma osmolality considered the gold standard - measures the concentration of solutes in plasma
What is Commonly used in sport settings to assess hydartion status? (4)
- urine osmolality
- urine specific gravity
- Rapid/overnight changes in BW: 1 kg ~ 1 L fluid or 1 L sweat
- urine colour chart
How do athletes
MINIMIZE BODY MASS LOSSES?
Try to keep body mass losses to no more than 2-3%
Calculate body weight loss during exercise:
* Body weight before exercise minus body weight after exercise = body weight loss
* Body weight loss / starting body weight *100
Example: Hockey player training for 1 hour
- 67kg before exercise – 64.5kg after exercise = 2.5kg body weight loss
- 2.5kg/67kg * 100 = 3.7%
Example: 1 Soccer player training for 1 hour
1. 82kg before exercise
2. 78.7kg after exercise
FLUID CHOICE DURING EXERCISE
What should your carb target be for
Short Exercise?
What should your carb target be for
Longer Duration Exercise?
What should your carb target be for
Stop and Start Sports?
What should your carb target be for
Ultra Endurance Sports?
