Nutrition & Athletic Performance Flashcards
1
Q
Nutrition plays an essential role in exercise and sport because it is important for:
A
- health
- adaptations to PA and exercise
- weight maintenance
- exercise performance
2
Q
Nutrition influences nearly every process in the body involved in:
A
- energy production
- recovery from exercise
3
Q
Timing and amount of intake of macronutrients in the athlete’s diet should be based on a fundamental understanding of:
A
- how training-nutrient interactions affect energy systems
- substrate availability
- training adaptations
4
Q
Exercise is fuelled by an integrated series of energy systems:
A
- ATP-PCr
- glycolysis
- aerobic
5
Q
ATP-PCr system:
A
provide a rapidly available energy source for muscular contraction for ~10 seconds
6
Q
Anaerobic glycolytic pathway:
A
- rapidly metabolizes glucose and muscle glycogen
- primary pathway supporting high intensity exercise lasting 10-180 seconds
7
Q
As _____ becomes more available to the working muscle, the body uses more of the _____ pathways and less of the _____ pathways.
A
- oxygen
- aerobic (oxidative)
- anaerobic (phosphagen and glycolytic)
8
Q
Oxidative pathways provide the primary fuels for events lasting longer than ______.
A
~2 minutes
9
Q
Oxidative pathways use:
A
- muscle and liver glycogen
- intramuscular lipid
- adipose tissue
- triglycerides and AA from muscle, blood, liver and the gut
10
Q
When crossover between pathways occur, the relative contribution of energy pathways is determined by:
A
- intensity, duration, frequency, and type of training
- sex and training level of the individual
- prior nutrient intake and substrate availability
11
Q
6 components of diet:
A
- carbohydrate
- protein
- fat
- vitamins
- minerals
- water
12
Q
Carbs can influence:
A
- performance
- adaptation to training
13
Q
Modern carb intake recommendations are….
A
not one size fits all
14
Q
Carb intake should be a function of …..
A
carb use or needs
15
Q
Carb daily needs/recommendations depend on:
A
- characteristics of the exercise session
- body weight (proxy for the size of muscle stores)
16
Q
General fuelling up guidelines:
A
- preparation for events <90 min exercise
- 7-12 g/kg per 24 h as for daily fuel needs
17
Q
What type of carbs for general fuelling up?
A
- carb rich sources
- low in fibre
- easily consumed to ensure that fuel targets are met
- meet goals for gut comfort or lighter racing weight
18
Q
Carb loading guidelines:
A
- prep for events >90 min of sustained/intermittent exercise
- 26-48 h of 10-12 g/kg body weight per 24 h
19
Q
Speedy refuelling guidelines:
A
- <8 h recovery between 2 fuel demanding sessions
- 1-1.2 g/kg/h for first 4 h then resume daily fuel needs
20
Q
What type of carbs for speedy refuelling?
A
- there may be benefits in consuming small regular snacks
- carb rich foods and drink may help to ensure that fuel targets are met
21
Q
Pre-event fuelling guidelines:
A
- before exercise > 60 min
- 1-4 g/kg consumed 1-4 h before exercise
22
Q
What types of carbs for pre-event fuelling?
A
- timing, amount, type of carb foods and drinks should be chosen to suit the practical needs of the event and individual preference/experience
- choices high in fat/protein/fibre may need to be avoided to reduce risk of GI issues during event
- low glycemic index choices may provide a more sustained source of fuel for situations where carbs cannot be consumed during exercise
23
Q
Scandinavian researchers discovered that muscle glycogen could be _____ by changes in _____ and _____.
A
- supercompensated
- diet
- exercise
24
Q
Supercompensation protocol resutled in….
A
extremely high muscle glycogen concentration
25
Important potential disadvantages of supercompensation:
- hypoglycemia during the low carb period
- GI problems
- poor recovery when no carbs are ingested
- tenseness during a week without training
- increased risk of injury
- mood disturbances during the low-carb period
26
Because of the numerous disadvantages of the classical supercompensation protocol, studies have focused on....
a more moderate protocol that can achieve similar results
- training slowly reduced over a 6 day period
- first 3 days: 50% CHO diet
- last 3 days: 70% CHO diet
27
How does supercompensation work?
- inc. time to exhaustion (endurance capacity) by ~20%
| - dec. time required to complete a set task (eg. time trial, endurance performance) by 2-3%
28
With supercompensation, the duration of exercise must be at least ___ minutes before performance benefits occur.
90
29
Supercompensation had no effect on....
- sprint performance and high-intensity exercise up to about 30 minutes
- at these high intensities, glycogen depletion is probably not the performance-limiting factor
30
Mechanisms by which CHO feeding during exercise may improve endurance performance:
- maintenance of blood glucose and high levels of carb oxidation
- glycogen sparing in the liver and possibly muscle
- promotion of glycogen synthesis during exercise
- affects motor skills
- affects the CNS
31
Carbs provide improvement in endurance and performance > ___ min of duration.
45
32
Amount of carbs needed during brief exercise (<45 min):
not needed
33
Amount of carbs needed during sustained high intensity exercise (45-75 min):
- small amounts including mouth rinse
| - frequent contact of carb with mouth
34
Amount of carbs needed during endurance exercise including stop and start sports (1-2.5 h):
- 30-60 g/h
35
Amount of carbs needed during ultra endurance exercise (>2.5-3 h):
- up to 90 g/h
| - products providing multiple transportable carbs achieve high rates of oxidation of carbs consumed during exercise
36
Type of CHO ingested can affect _____ and _____ ___ and consequently improve _____.
- absorption
- oxidation rates
- performance
37
Feeding a single CHO source at high rates saturate _____ and limits _____.
- transporters
| - absorption
38
____ + _____ + ______ + _____ + _____ = more CHO absorbed, made available for oxidation.
- glucose
- fructose OR maltodextrin
- fructose OR glucose
- sucrose
- fructose
39
Effect of more CHO absorbed, made available for oxidation is attributed to ....
the separate transport mechanisms across the intestinal wall for glucose (SGLT1) and fructose (GLUT5)
40
Faster absorption ____ the amount of CHO in the ___ ____ = dec. ____ discomfort during exercise.
- decrease
- GI tract
- GI
41
Describe carb mouth rinse:
- CNS might sense the presence of carbs via receptors in the mouth and oral space
- sweet and non-sweet CHO were shown to activate regions in the brain associated with reward and motor control
- rinsing the mouth with a carbohydrate solution can enhance performance
42
Describe how mouth rinsing or ingesting small amounts of CHO play a role when high power output is required over 45-75 minutes.
non-metabolic role in enhancing performance by ~2-3%
43
Mouth rinse can be practical in a few situations:
- athlete cannot ingest any CHO because of GI problems
| - energy intake needs to be restricted
44
In carb mouth rinse, ____ is not the key factor.
- sweetness
| - artificial sweeteners do not affect performance
45
In carb mouth rinse, brain activity is specific to ____.
- carbohydrates
| - other nutrients do not seem to affect performance
46
Purpose of CHO intake after PA:
replenish depleted stores of liver and muscle glycogen
47
Important factors in promoting restoration of muscle glycogen stores:
- timing of CHO intake
- rate of CHO ingestion
- type of CHO ingested
- ingestion of PRO and CHO after exercise
48
Glycogen synthesis (4-6 h) post exercise is dependent on _____ _____. Above ____ of carb intake, there is little or no further benefit.
- carb intake
| - 1.2 g/kg bw/h
49
Ingestion of types of carbs have no effects on ____ ____.
glycogen synthesis
50
Fructose ingestion leads to lower rates of ...
muscle glycogen synthesis after exercise compared with glucose or sucrose
51
Fructose must be converted to _____ in the ____ before it can be used for ____ synthesis in the muscle. This process takes time.
- glucose
- liver
- glycogen
52
____ rate and the ____ of glucose seem to be important factors for glycogen synthesis.
- absorption
| - availability
53
Muscle glycogen is more restored with a ____ meal compared with a ____ meal.
- high GI meal
| - low GI meal
54
____ or ____ CHO meal have the same effect.
- liquid
| - solid
55
Glycogen storage is increased when carbohydrate is ingested with _____.
protein
56
Certain ___ have a potent effect on the secretion of insulin.
AA
57
Fat is a necessary component of a healthy diet, providing...
- energy
- essential elements of cell membranes
- facilitation of the absorption of fat-soluble vitamins
58
Intake of fat by athletes should be in accordance with ___ ____ guidelines and should be ____ based on ____ ____ and ____ ____ goals.
- public health
- individualized
- training levels
- body composition
59
Fat is an important fuel for ____ exercise.
endurance
60
In some forms of exercise (eg. prolonged cycling or running), ____ depletion is a possible cause of ____. Depletion can occur within ___ h of strenuous exercise.
- CHO
- fatigue
- 1-2
61
Total amount of energy stored as glycogen in the muscles and liver has been estimated to be ____.
1912 kcal
62
Fat stores can contain more than ____ times the amount of energy contained in CHO stores.
50
63
During exercise, CHO and fat are always _____ as a ____. There is no switch. The two substrates are always used _____.
- oxidized
- mixture
- simultaneously
64
Depending on the ____ and ______, one substrate may contribute more than the other.
- conditions
| - availability
65
Whether CHO or fat is the predominant fuel depends on a variety of factors including:
- intensity and duration of exercise
- aerobic capacity
- diet
- CHO intake before or during exercise
66
Fat oxidation increases as ____ ____ increases. Possibly due to a decrease in ____ ____ ____.
- exercise duration
| - muscle glycogen stores
67
At low exercise intensities, ____ is the predominant fuel.
fat
68
At 25% of VO2 max....
most of the fat oxidized is derived from plasma FAs
69
At 65% of VO2 max....
the contribution of plasma FAs declines and the contribution of IMTGs increases and provides 1/2 of the FAs used for total fat oxidation
70
At high exercise intensities, ____ are the major fuel.
CHO
71
At > 75% of VO2 max, ____ oxidation is inhibited.
fat
72
Chronic diets (~5 days) can have marked effects on metabolism. Effects partly related to:
- effects of diets on substrate availability
| - adaptations at the muscular level
73
High CHO, low fat diet leads to....
decreased fat oxidation
74
Low CHO, high fat diet leads to....
increased fat oxidation
75
Fastest way to alter fat metabolism during exercise is....
by CHO feeding
76
CHO ingestion --> increase ____ --> decrease _____ --> decrease _____ --> decrease _____ _____.
- insulin
- lipolysis
- FA availability
- fat oxidation
77
Longer term manipulations of the diet that last days or weeks can increase ____ ____ and decrease reliance on ____ ____ during exercise.
- fat oxidation
| - CHO stores
78
Examples of longer-term manipulations:
- fasting
- short-term high-fat diet
- long term high-fat diet
- ketogenic diet
79
Short term fasting has been proposed as a way to:
- increase fat use
- spare muscle glycogen
- improve exercise performance
80
Fasting --> increase ____ --> increase _____ --> increase ______ --> increase ___ _____.
- circulating catecholamines
- lipolysis
- circulating FAs
- fat oxidation
81
Muscle glycogen concentrations are unaffected by fasting for 24 hours when ....
no strenuous exercise is performed
82
Liver glycogen stores are substantially depleted after a ____ ____. Why?
- 24 h fast
| - euglycemia not maintained during exercise
83
Fasting has no effect on endurance capacity at ____ exercise intensities (___% of VO2 max) but decreases performance at _____ exercise intensities (___% of VO2 max).
- low
- 45%
- higher
- 50-100%
84
Short term high-fat diet results in:
- dec. muscle glycogen levels
- inc. lipolysis = inc. plasma (FA and glycerol)
- inc. uptake of FA by the muscle
- elevated plasma levels of ketone bodies
- inc. breakdown of muscle triacylglycerols
85
Impaired performance or endurance capacity with short term high fat diet includes:
- reduction in muscle and liver glycogen stores
- poor recovery
- increases in RPE
86
Longer term (weeks) high fat diets are thought to result in adaptations that will....
restore exercise tolerance
- dec. use of CHO
- inc. contribution of fat to energy metabolism
87
Although long-term high fat diets induce ______ adaptations in skeletal muscle that favour ____ oxidation, the effects on performance may not be visible because of :
- enzymatic
- fat
- suboptimal muscle glycogen levels
- suboptimal adaptations to the training
88
Increase in fat oxidation can be the result of:
- depletion of CHO stores
- inability to use CHO
- in these cases, improved fat oxidation is linked with a decrease in performance
89
What is a ketogenic diet?
- high-fat, moderate to low protein, and very low CHO diet (< 50 g of CHO per day)
- ratio 3:1 or 4:1 (fat to CHO+protein)
- forces the body to oxidize fat instead of glucose for energy production
90
A ketogenic diet forces the body to be in _____ _____.
physiological ketosis
91
Fat metabolism occurs via the oxidation of ____ by the ____ producing ____ ____.
- FAs
- liver
- ketone bodies
92
3 ketone bodies:
- B-hydroxybutyrate
- acetoacetate
- acetone
93
3 ketone bodies are transported to tissues where they are converted to ____, which is a substrate in the first step of the ____ ____.
- acetyl-CoA
| - Krebs cycle
94
How the ketogenic diet affects performance:
most found no difference or decreases
95
How does dietary protein interact with exercise?
- provides a trigger and a substrate for the synthesis of contractile and metabolic proteins
- enhances structural changes in non-muscle tissues such as tendons and bones
96
Adaptations from dietary protein are thought to occur by stimulation of the activity of the _____ _____ _____ in response to a rise in _____ concentrations and the provision of an exogenous source of ____ for incorporation into new proteins.
- protein synthetic machinery
- leucine
- AA
97
Skeletal muscle is a critical organ for ____ and ____ health. Associated with ____ ____ and _____.
- physical
- metabolic
- good health
- longevity
98
The size of human muscle mass is dictated by...
- changes in rates of MPS and MPB
| - collectively referred to as turnover
99
In response to protein feeding + exercise, there is an increase in rates of _____ and a mild suppression of ____.
- MPS
| - MPB
100
RE training results in:
- increases in strength
| - increases in muscle fibre cross-sectional area
101
EE training is characterized by fatigue resistance due in part to:
increased oxidative capacity secondary to increased mitochondrial density and thus mitochondrial protein
102
Acutely, the rate of mixed ____ is stimulated by ___ and ____.
- MPS
- RE
- EE
103
RE and EE must induce ____ _____ in differing fractions of muscle protein, most obviously _____ vs _____ proteins.
- protein synthesis
- myofibrillar
- mitochondrial
104
Current data suggest that dietary protein intake necessary to support ____ ____, _____, _____, and for _____ ____ generally ranges from ____. Higher intakes may be indicated for ....
- metabolic adaptation
- repair
- remodelling
- protein turnover
- 1.2 to 2.0 g/kg/d
- short periods during intensified training or when reducing energy intake
105
Those involved in ____ training might need to consume more protein than those undergoing ___ training.
- RE
| - EE
106
EE can increase whole body ____ ____ of ___ that must ultimately be replaced via ____ ____. This may contribute to the increase protein requirements of endurance athletes.
- oxidative disposal
- AA
- dietary sources
107
Consumption of ___ of protein enhance _____ remodelling after all forms of exercise.
- ~0.31 g/kg
| - myofibrillar
108
Depending on individuals; ____ ___ and ____ ___, protein dose can change.
- body weight
| - lean mass
109
The relative protein intake per meal to maximally stimulate postprandial rates of MPS is ____ for young adults and ____ for older adults.
- ~0.24 g/kg
| - ~0.40 g/kg
110
RE alone results in a long-lasting elevation in ____ for at least ____ hours and ____ for ____ hours.
- MPS
- 48 hours
- MPB
- 24 hours
111
RE will prime the muscle to be ____, in terms of an increased sensitivity of ____ to _____. The duration of this sensitivity is at least ___ hours.
- prime
- MPS
- aminoacidemia
- 24
112
The ____ of protein intake is an important variable to consider in optimizing skeletal muscle ___ and ____.
- timing
- recovery
- hypertrophy
113
It appears optimal to ingest protein in the ____ period though the supposed _____ window for protein ingestion lasts at leas ____ hours.
- post-exercise
- anabolic
- 24
114
It is also important to ingest protein in ______ doses distributed throughout the day (___ meals/day).
- sufficient
| - 4
115
There appears to be a leucine threshold for stimulation of ___ that is around ____g/meal, which may be determining the per meal protein recommendation of ____ g protein/kg.
- MPS
- ~3 g/meal
- ~0.4 g protein/kg
116
Pre-sleep feeding is a time when....
protein provision may provide a marked benefit to remodel muscle proteins
117
Ingesting AAs in larger doses of protein pre-sleep appears to...
increase acute overnight MPS and chronic skeletal muscle adaptations
118
High quality, rapidly digested protein sources (egg, whey) elicits an ____ and ____ post exercise stimulation of ____ ____ _____.
- early (w/i 3 h)
- robust
- muscle protein synthesis
119
High quality dietary proteins are effective for the _____, _____, and _____ of skeletal muscle proteins.
- maintenance
- repair
- synthesis
120
There are reports of increase MPS and protein accretion with:
- whole milk
- lean meat
- dietary supplements (whey, casein, soy, albumin)
121
Recent focus has been placed on the importance of studying whole foods (eg. egg, beef). Why?
- nutrient dense
| - more representative of normal habitual dietary patterns
122
As the peak and/or the rate of change in ____ ____ ____ regulates post-exercise muscle protein synthesis, the typically delayed ____ and ____ of solid foods may result in an _____ muscle protein synthetic response.
- blood AA concentration
- digestion
- absorption
- decreased
123
_____ ____ may not be the only variable that influences the anabolic potential of whole food.
digestion rate
124
Minced beef has been demonstrated to induce a more rapid ____ ____ than skim milk.
postprandial aminoacidemia
125
Whole milk has been demonstrated as more ____ than skim milk and skim milk more _____ than soy juice during ____ ____ ____.
- anabolic
- anabolic
- post exercise recovery
126
Whole egg supports a greater _____ _____ protein synthetic response than an isonitrogenous quantity of egg white protein.
post exercise myofibrillar
127
There may be circumstances whereby ____, ___ dense foods may require a ____ relative intake to maximize post exercise anabolism than other isolated protein sources.
- whole
| - nutrient
128
There are differences in quality between the 3 most commonly consumed isolated protein sources:
- whey
- soy
- casein
129
____ and ___ are digested rapidly, resulting in rapid _____, and induce a larger but more transient rise in ____ than ____.
- whey
- soy
- aminoacidemia
- MPS
- casein
130
Whole-body protein synthesis is stimulated more with ____ protein whereas whole body protein breakdown is suppressed with ingestion of ____.
- whey
| - casein
131
The slower and more prolonged aminoacidemia accompanying the ingestion of _____ may be more effective at sustaining ____ and possibly at attenuating _____ net protein balance over longer periods of time.
- casein
- MPS
- negative
132
It appears that post-exercise MPS, measured within 3 h is optimized by protein ingestion that contains...
a high leucine content where proteins are rapidly digested (ie. whey)
133
Cooked meats with highest protein quality:
beef
134
Cooked fish with highest protein quality:
- salmon
| - white fish
135
Dairy with highest protein quality:
- cheddar cheese
- feta cheese
- cottage cheese
- goat's milk
- cow's milk
136
boiled vegetables with highest protein quality:
soybeans
