Lecture Slides - Nutritional Ergogenics Flashcards
1
Q
Caffeine is a ___ drug; it can affect a variety of metabolic and psychological processes that impact exercise and performance
A
stimulant
2
Q
What is an effective dose of caffeine?
A
approximately 3-6 mg/kg BW
3
Q
What is the mean consumption of caffeine per day in NA?/
A
106-170mg/day
4
Q
peak plasma levels of caffeine happen within __-__ minutes
A
15-45 minutes
5
Q
what is the half life of caffeine? since it is such a wide range, what does this mean about when people can drink it?
A
2.5-7.5 hours - this is why some people can drink it in the evening and still fall asleep fine when others have to stop drinking it around 1-2pm
6
Q
where is caffeine metabolized?
A
within the liver
7
Q
how much caffeine (in mg) do the following have (all 8oz except 2oz espresso):
- double espresso
- brewed coffee
- instant coffee
- decaf coffee
- black tea
- green tea
A
45-100 mg 60-120 mg 70 mg 1-5 mg 45 mg 20 mg
8
Q
caffeine is extensively used in sports and athletics - until 2006, the WADA banned urine levels of >__ug/mL
A
12 (this is 2x the effective dose)
9
Q
Why did WADA lift the caffeine ban in competition?
A
cultural pervasiveness of habituation
10
Q
caffeine or energy drink + alcohol: two things the combo increases and one thing it decreases
A
- increases alcohol intake and use of other drugs and increases likelihood of harm to self and others
- decreases self-perceived level of drunkenness
11
Q
Caffeine increases ___ and spares ____ ____
A
lipolysis; muscle glycogen
12
Q
Caffeine increases excitability of the ____ _____
A
muscle fibers
13
Q
Caffeine influences signal transduction from the _____ to the ____ ____
A
brain to the motor neuron
14
Q
What are the three suggested caffeine mechanisms? (KNOW THESE)
A
- Caffeine increases lipolysis and spares muscle glycogen
- Caffeine increases excitability of the muscle fibers
- Caffeine influences signal transduction from the brain to the motor neuron
15
Q
Individuals who normally do not use caffeine may experience side effects; these are all caused by effects on the _____
A
CNS
16
Q
Very high intakes of caffeine have been associated with what 4 things?
A
- peptic ulcers
- seizures
- coma
- death
17
Q
what is one of the main central side effects of caffeine?
A
sleep deprivation
18
Q
The diuretic effect of caffeine is minimized with the use of _____ ____
A
anhydrous caffeine
19
Q
Is there a diuretic effect observed in habituated users?
A
nopers
20
Q
During exercise, the diuretic effect of caffeine is counteracted by _______
A
catecholamines
21
Q
Males are approximately ___% water by body weight
Females are about ___% water by body weight
A
60%
50%
22
Q
Does % of body water increase or decrease in obese people? muscular people?
A
decrease; increase
23
Q
4 ways we lose fluid and 3 ways we gain it? (mention mL)
A
Lose: respiration (200), skin (600), feces (100), urine (1300)
Gain: drink (1200), food (700), metabolic (300)
24
Q
__-__% of a healthy adult is fluids. 2/3 of this fluid is in one place and the other 1/3 is in another, where are these places?
A
50-60%
2/3 - intracellular fluid
1/3 - extracellular fluid
25
body fluid is composed of ____ and ____
water and electrolytes
26
"ions and mineral salts dissolved in water"
electrolytes
27
Give some examples of electrolytes (5)
- sodium
- chloride
- potassium
- magnesium
- calcium
28
What is the function of fluids in the body? Give some examples.
protect body tissues
- CSF protects the CNS
- amniotic fluid protects the fetus
- synovial fluid in joints
- urine production to eliminate waste
- sweat for exercise thermoregulation
29
What are the 3 functions of electrolytes?
-critical for nerve function
muscle contractions
-regulation of fluid balance
30
Water follows ____; osmosis
electrolytes
31
```
Normothermia = __-__ degrees celsius
Hyperthermia = ?
Hypothermia = ?
```
36.5-37.5
higher than normal
lower than normal
32
__ °C = upper limit for life
__ °C = voluntary upper limit
__ °C = lower limit for life
__ °C = change in CT is physiologically significant
43°C
41°C
34°C
0.1°C
33
blood flow directed to skin stimulates _____
sweating
34
Blood flow during exercise is reduced to what areas of the body?
the viscera (including the brain)
35
Blood flow changes during thermal challenge (exercise) will reduce functional ____ _____.
cardiac output
36
Ventilatory changes during thermal challenge (exercise) is approximately ___% increase - this is referred to as what?
20% - "selective brain cooling"
37
___-___% of metabolic energy produces heat
70-80%
38
If contained within the body, core temperature would increase __°C every 5 minutes
1°C
39
What are the four heat loss mechanisms?
evaporation, radiation, conduction, convection
40
2-4 million sweat glands secrete __-__+ L/hour. This is up to how many L/day?
0.5-4.0 L/hour
| 8-12 L/day
41
Where do sweat glands pull moisture from?
body cells and blood plasma
42
Sweat is affected by what? (name at least 3 things)
- fitness
- temperature
- humidity
- exercise intensity
- heat acclimation
- hydration status
- air velocity
- type of clothing
43
How does sweat evaporate from the skin?
water vapour pressure gradient on the skin (pressure difference between water vapour pressure on skin and in air)
44
What formula can be used to estimate sweat rate?
Pre activity weight - post activity weight + urine output (L) - fluid consumed (L)
45
What are normal sweat rates in L/hour for MVPA?
1-3 L/hour
46
If environmental humidity is >__% evaporation is ineffective
70
47
Sweat must ____ to be effective
evaporate (rolling off is not effective)
48
A loss of _-_% of body weight in fluid, this is when we get the ___ signal
1-2
49
A loss of 2% or more fluid causes what?
muscle weakness - lose significant strength and endurance
50
A loss of 10-12% of fluid causes what?
heat intolerance
51
A loss of __% of body fluid causes what?
20%
52
```
What is the exercise capacity if this amount of body weight is lost?
1%:
2%:
3%:
4%:
5%:
```
```
1%: 96% work capacity
2%: 92% work capacity
3%: 88% work capacity
4%: 80% work capacity
5%: 75% work capacity
```
53
How much water per day for a sedentary male vs female? What about during exercise?
M: 3.7L
F: 2.7L
-during exercise you should drink amount lost +50% to account for incomplete absorption
54
gastric emptying rates for fluid = __ - __ mL/hour
500-1000mL/hr
55
voluntary consumption during exercise = __-__mL/hour
300-500
56
when active > 60 minutes, drink __-__mL every 15 minutes
125-250 (this is about two mouthfuls)
57
"condition of subnormal levels of sodium in the blood"
hyponatremia
58
At rest, how can hyponatremia occur?
due to consuming too much water - this is known as water intoxication
59
What do symptoms of prolonged exercise associated hyponatremia look like? What would a sever case look like?
Symptoms: bloating puffiness of hands/feet, nausea, vomiting, headache
Sever cases: massive brain swelling - might be associated with seizures, coma, respiratory arrest, permanent brain damage, and death
60
Risk factors of endurance events?
- excessive fluid intake
- considerable weight gain over event
- slower finishers
- lower body weight
- high sweat sodium losses
- NSAID
61
Electrolyte recommendations for fluid in rehydration solutions and during exercise of >1 hour:
- [sodium] of ___-___mg/L
- [potassium] of __-__mg/L
460-690 mg/L
| 78-195 mg/L
62
T/F: Athletes should liberally salt their foods unless another sodium restriction is in place
True!
63
T/F: potassium is reasonably easy to get from food
true
64
AI and UL for sodium.
```
AI = 1500 mg
UL = 2300 mg
```
65
Table salt is __% sodium and __% chloride
40%
| 60%
66
Sodium is the primary positive ion in _____ fluid and plays an important role in what 4 bodily functions?
extracellular;
- nerve impulses
- muscle contraction
- acid-base balance
- blood volume homeostasis
67
What are some sodium rich foods?
- olives
- soy sauce
- pizza slice
- canned soups
68
What is the AI for potassium?
4700 mg
69
Potassium is the primary positive ion in ___ fluid and is responsible for what bodily functions?
intracellular;
| -same functions as sodium, but intracellular, and is also involved in glucose transport into cell
70
Potassium rich foods?
- skim milk
- yogurt
- banana
- citric juices
- oranges
- raisins
- baked potato
71
ACSM pre exercise recommendations: 24 hours
consume nutritionally balanced diet and drink adequate fluids to promote proper hydration
72
ACSM pre exercise recommendations: greater than or equal to 4 hours before
5-7mL/kg BW (IMPORTANT- know this)
73
If by 2 hours before exercise the individual does not produce urine OR if urine appears highly [ ], then what should the athlete do?
consume an additional fluid amount of 3-5 mL/kg BW
74
Beverages containing sodium together with salted foods may help with what?
stimulate thirst and enhance fluid retention
75
If dehydration or hyperthermia are a threat, what should you treat with?
water replacement is the primary consideration
76
During prolonged endurance events that use muscle glycogen as the primary energy source, replacement of what is key?
CHO
77
During very prolonged and ultra-endurance events in heat with heavy sweat loss, what replacement is key?
electrolyte replacement may be essential to prevent heat injury
78
During exercise, what 5 factors affect gastric emptying and absorption rates?
```
volume
concentration
temperature
exercise intensity
hydration status
```
79
During exercise, increasing the volume of liquid ingested (up to 500-1000mL/hr) will increase or decrease gastric emptying?
increase
80
What concentration of CHO solution will cause a decrease in gastric emptying?
6-8% has no averse effects
9-10% is when we start to see a decrease in emptying rates
81
Do warm or cool liquids empty faster?
cool fluids (approx 15 degrees celsius) - may confer some cooling advantage
82
What exercise intensity tends to decrease emptying rates?
70-75% VO2 max
83
Dehydration beyond a __% loss of BW may start to decrease gastric emptying
3%
84
The main factors influencing effectiveness of rehydration strategies are ____ and ____ of fluid
volume and composition
85
Plain water alone after exercise is not ideal, why?
- water alone causes rapid decreases in plasma [sodium] and osmolarity
- results in decreased stimulation to drink, as well as an increase in urine output
86
Gatorade:
[CHO] g/L =
[NaCl] g/L =
[K] g/L =
64
1. 05
0. 1
87
Powerade:
[CHO] g/L =
[NaCl] g/L =
[K] g/L =
58
1. 05
0. 1
88
High recipe:
[CHO] g/L =
[NaCl] g/L =
[K] g/L =
100
1. 75
0. 195
89
Low recipe:
[CHO] g/L =
[NaCl] g/L =
[K] g/L =
50
1. 17
0. 078
90
ACSM:
[CHO] g/L =
[NaCl] g/L =
[K] g/L =
50-100
1. 17-1.75
0. 078-0.195
91
What is a good example of a dietary nitrate?
Beetroot! Green leafy vegetables are also great.
92
Beetroot typically contain over ___mg nitrate per 100g fresh weight
250
93
Following ingestion, nitrate is converted in the body to _____
nitrite
94
where is nitrite stored?
stored and circulated in the blood
95
NO plays a number of important roles in ____ and ____ control
vascular and metabolic
96
What are the 5 steps in digestion and absorption of nitrates?
1. Ingested inorganic nitrate absorbed in plasma (JEJUNUM)
2. Approx. 25% is taken up by the salivary glands and concentrated 10x (PAROTID GLAND - in mouth)
3. Commensal Facultative Anaerobic bacteria residing in the crypts on surface of tongue reduce nitrate to nitrite (MOUTH)
4. Some is reduced to NO in acid of stomach
5. Most nitrite enters the systemic circulation, elevating plasma [NO2]
97
Dietary nitrate supplementation increases ___ ___ concentration and reduces resting ___ ___
plasma nitrite ; blood pressure
98
Nitrate supplementation reduces the _____ ____ of submaximal exercise
oxygen cost - in some circumstances, it can even enhance exercise tolerance and performance
99
Following nitrate ingestion, when does plasma [nitrate] peak, what about plasma [nitrite]?
1-2 hours - nitrate
| 2-3 hours - nitrite
100
After peak, both plasma [nitrate] and [nitrite] fall back to baseline values in __hrs
approximately 24 hours
101
NO can modulate skeletal muscle function by doing what 5 things?
- regulation of blood flow
- contractility
- glucose regulation
- calcium homeostasis
- mitochondrial respiration and biogenesis
102
Consuming approximately __-__ mmol of nitrate/day for 1-15 days can elicit favorable effects
5-9 = this amount can readily be consumed in the diet
103
____ ___ decreases muscle acidity and increases the buffering capacity of blood
sodium bicarbonate
104
When are the ergogenic effects of sodium bicarbonate seen?
- single bout of supramax exercise
- high intensity intermittent activity
- skill based sports
105
Bicarbonate buffers H- ions in the _____
blood (NOT MUSCLE)
106
What is the optimum dosage and when should you take it before exercise?
300 mg/kg BW at approximately 1-3 hours pre exercise
107
What are 3 side effects of using sodium bicarbonate to supplement during exercise?
bloating
abdominal discomfort
diarrhea
