Athletic Performance Nutrition Exam #3 Flashcards
1
Q
Mechanisms for Temperature Regulation: stimulated by heat
A
- Increases heat loss ->
vasodilation of subcutaneous skin vessels; sweating - Decreases heat production -> decreased muscle tone & voluntary activity; decreased thyroxine & epinephrine secretion
2
Q
Mechanisms for Temperature Regulation: stimulated by cold
A
- Decreases heat loss -> Vasoconstriction of skin vessels; postural reduction of surface area (curling up)
- Increases heat production -> Shivering and increased voluntary activity; increased thyroxine and epinephrine secretion
3
Q
How does the body primarily protect itself from overheating
A
Using the body’s thermoregulatory mechanisms
4
Q
Deep tissue or core body temp represents a dynamic equilibrium between factors that add & subtract body heat. What are the 3 integrating mechanisms that thermal balance results from?
A
- Alter heat transfer to the periphery or shell
- Regulate evaporative cooling
- Vary heat production rate
5
Q
During sustained PA for aerobically fit men & women, metabolism often increases to how much above resting level?
A
20-25x above resting level or 20kcal/min
6
Q
What will heat production of this magnitude theoretically increase core temperature by?
A
1 degree Celsius every 5 to 7 minutes
7
Q
What does the hypothalamus contain?
A
The central neural coordinating center for temperature regulation
8
Q
What are the 4 ways the body loses heat?
A
- Radiation
- Conduction
- Convection
- Evaporation
9
Q
Do objects continually emit electromagnetic heat waves?
A
Yes
10
Q
How does the body transfer heat directly using conduction?
A
Through liquid, solid, or gas from one molecule to another
11
Q
What does this group of specialized neurons at the floor of the brains serve as?
A
“Thermostat” (usually set & carefully regulated at 37 degrees Celsius +or- 1 degree; 98.6 degrees Fahrenheit +or- 1.8 degreees
12
Q
What does the rate of conductive heat loss depend on?
A
It depends on a temperature gradient between the skin and surrounding surfaces and their thermal qualities
13
Q
What 2 ways cause heat-regulating mechanisms to become activated?
A
- Temp changes in blood perfusing the hypothalamus directly stimulate this thermoregulatory control center
- Thermal receptors in the skin provide input to modulate hypothalamic activity
14
Q
When does sweating start during vigorous activity?
A
Sweating begins within several seconds
15
Q
What occurs with sweat after 30 mins of vigorous activity?
A
Sweating reaches an equilibrium directly related to exercise load
16
Q
What does the effectiveness of of heat loss by conduction via air depend on?
A
How rapidly air near the body exchanges once it warms
17
Q
How many sweat or eccrine glands are there?
A
2-4 million
18
Q
What does evaporation of sweat provide?
A
The major physiological mechanism for heat loss & thus defense against overheating
19
Q
What does the posterior pituitary gland do during heat exposure?
A
It recreates antidiuretic hormone (ADH), which increases water reabsorption from the kidney tubules to create more concentrated urine
20
Q
What does hot weather stimulate?
A
It stimulates the adrenal cortex to release the sodium-conserving hormone aldosterone, which increases sodium reabsorption by the renal tubes
21
Q
What do sweat glands secrete in large quantities in response to heat stress?
A
Hypotonic saline solution (0.2 to 0.4% NaCl)
22
Q
How many ml of water seeps through the skin each day and evaporates to the environment?
A
350ml
23
Q
What are the 5 factors other than air temperature that determine heat-imposed physiologic strain?
A
- Body size and fatness
- Level of training
- Acclimatization
- Adequacy of hydration
- External factors (convective air currents; radiant heat gains; intensity of activity; amount, type, and colour of clothing; and most importantly, relative humidity)
24
Q
What is water seeping through the skin called?
A
Insensible persperation
25
How many ml of water vaporizes daily from the respiratory passages moist mucous membranes?
300 ml of water
26
What 3 factors determine sweat evaporation from skin?
1. Surface area exposed to the environment
2. Ambient air temp & relative humidity
3. Convective air currents around the body
27
Does relative humidity exert the greatest impact on the effectiveness of evaporative heat loss?
Yes, by far
28
What is the most effective way to minimize or eliminate heat stress injuries?
Prevention
29
Does large sweat output and subsequent fluid loss occur in sports other than distance running?
Yes, football, basketball, and hockey players also lose large quantities of fluid during practice or competitions
30
What is relative humidity?
The percentage of water in ambient air at a particular temperature compared to the total quantity of moisture the air could carry (ex: 40% humidity means ambient air contains only 40% of air’s moisture-carrying capacity at specific temp)
31
Does sweat cool the skin or does skin cooling occur only when sweat evaporates?
Skin cooling occurs only when sweat evaporates
32
Does continually drying the skin with a towel before sweat evaporates also thwart evaporative cooling?
Yes
33
Does the circulatory system serve as the main “workhorse” to control thermal balance?
Yes
34
With extreme heat stress, 15-25% of the cardiac output passes through the skin, greatly increasing the thermal conductance of peripheral tissues. T/F
True
35
Can heat generated by active muscles raise core temperature to fever levels that incapacitate a person if caused by external heat stress alone?
Yes
36
What 5 changes in body function coincides with the body fluid loss?
1. Decreased plasma volume
2. Reduced skin blood flow for a given core temperature
3. Reduced stroke volume of the heart
4. Increased HR
5. General deterioration in circulatory and thermoregulatory efficiency during physical activity
37
More than likely, will a modest rise in core temp reflect a favorable internal adjustment that will create an optimal thermal environment for physiologic & metabolic functions?
Yes
38
What is dehydration?
An imbalance in fluid dynamics when fluid intake doesn’t replenish water loss from either hyperhydrated or normally hydrated states.
39
How much sweat loss occurs over a 1-hour period during moderate PA?
0.5-1.5 L sweat loss
40
Does dehydration correlate with 3% decrease in body weight, which slows gastric emptying rates, thus triggering of epigastric cramps & nausea?
Yes
41
Does adequate fluid replacement sustains evaporative cooling of acclimatized humans? Properly scheduling fluid replacement maintains plasma volume so circulation seating progress? - T/F
True
42
Sweat is hypotonic with other body fluids, so reduced plasma volume caused by sweating correspondingly increases blood plasma osmolality T/F
True
43
Intracellular & extracellular compartments contribute to any fluid deficit (dehydration) that can reach levels that impede heat dissipation, reduce heat tolerance, & severely compromise cardiovascular function & exercise capacity. The risk of heat Illness increases greatly when a person begins activity in a dehydrated state. T/F
True
44
What does 1-pound weight loss represents?
450 mm of dehydration
45
Does the risk of heat illness increase greatly when a person begins activity in a dehydrated state?
Yes
46
What is the recommended fluid intake?
15 mins hourly loses up to 1000 mm, whereas fluid ingestion at 10 min intervals optimizes replenishing fluid loss in excess of 1000 mL per hr
47
When left on their own do most individuals voluntarily replace only about half of the water lost (<500ml/h) during PA?
Yes
48
How long would it take to reactive fluid balance if rehydration was left entirely to a person's thirst?
Several days following severe dehydration to re-establish fluid balance.
49
Does a well-hydrated individual always function at a more optimal physiologic & performance level than a dehydrated one?
Yes
50
What are “cold treatments”?
Periodic application of cold towels to the forehead & abdomen during PA, or taking a cold shower before exercising in a hot environment.
51
What three beverages do boys voluntarily consume after physical activity, dehydration, and heat exposure?
1. Plain water
2. Grape-flavoured water
3. Grape-flavoured water containing 6% carbohydrate
52
How much water should be drunk to compensate for water lost during activity?
Enough liquid to equal at least 125 to 150% of the amount of body weight lost during physical activity. The 25 to 50% "extra" water accounts for that portion of ingested water lost in urine
53
Does ingesting “extra” water (hyperhydration) before PA in a hot environment protect against heat stress?
Yes
54
What 3 effects does hyperhydration foster?
1. Delays dehydration
2. Increases sweating during PA
3. Minimizes core temp increase
55
Do these 3 hyperhydration effects enhance performance & overall safety?
Yes
56
What are recommendations for consuming water 24 hours before PA in heat and 20 minutes before?
24hr: Increase fluid intake
20min: 400-600ml of cool water
57
Do “cold treatments” facilitate heat transfer at the body’s surface when compared with the same PA without skin wetting?
No
58
In intense endurance activities in the heat, matching fluid loss with fluid intake often becomes impossible, because only about 1000ml of fluid each hour empties from the stomach. T/F
True
59
Do body weight changes indicate the extent of water loss from PA & adequacy of rehydration during & after activity of athletic competition?
Yes
60
What does voiding small volumes of dark yellow urine with a strong odor indicate?
A qualitative indication of inadequate hydration (well-hydrated individuals produce urine in large volumes, light in color, & w/out noticeable smell)
61
What provides the most effective defense against heat stress by balancing water loss with water intake rather than by pouring water over the head/body?
Adequate hydration
62
Does a moderate amount of sodium added to a rehydration beverage provide more complete rehydration after PA & thermal-induced dehydration than plain water?
Yes
63
When does restoring water & electrolyte balance in recovery occur most effectively?
By adding moderate to high amounts of sodium to the rehydration drink (100 moles/L, an amt exceeding commercial drinks) or by combining solid food with appropriate sodium content & plain water
64
With the kidneys continually forming urine should ingested fluid volume following PA exceed sweat loss by 25-50% to restore fluid?
Yes
65
Can some individuals produce relatively highly concentrated sweat regardless of their degree of acclimatization?
Yes
66
What does the development of hyponatremia require?
Extreme sodium loss through prolonged sweating coupled with dilution of existing extracellular sodium and accompanying reduced osmolarity form consuming large fluid volumes containing low or no sodium
67
What are the 4 factors that are a concern during hot-weather physical activity?
1. Dehydration
2. Decreased plasma volume and resulting hemoconcentration
3. Impaired physical performance and thermoregulatory capacity
4. Increased heat injury risk (especially heat stroke)
68
What happens with repeated exposure to hot environments combined with physical activity?
Improves exercise capacity with less discomfort upon heat exposure
69
What is heat acclimatization?
The physiologic adaptations that improve heat tolerance
70
What is the effect of the acclimatization response to improved cutaneous blood flow?
Transport metabolic heat from deep tissues to the body's shell
71
What does Figure 10.10 show?
That major acclimatization to heat stress occurs during the first week of heat exposure (2-4 hr daily) with essentially complete acclimation after 10 days. In practical terms, use 15-20 mins of light-intensity physical activity during the first several sessions in a hot environment
72
What is the effect of the acclimatization response to effective distribution of cardiac output?
Appropriate circulation to skin and muscles to meet demands of metabolism and thermoregulation; greater stability of blood pressure during exercise
73
What is the effect of the acclimatization response to lowered threshold for start of sweating?
Evaporative cooling begins early during exercise
74
What is the effect of the acclimatization response to more effective distribution of sweat over skin surface?
Optimum use of effective surface for evaporative cooling
75
What is the effect of the acclimatization response to increased sweat output?
Maximizes evaporative cooling
76
What is the effect of the acclimatization response to lowered salt concentration in sweat?
Frees greater portion of cardiac output for distribution to active muscles
77
What is the effect of the acclimatization response to less reliance on carb catabolism during exercise?
Carb-sparing effect
78
Does colour play an important role in radiant heat gain?
Yes; dark colours absorb more heat as light rays (energy) and add to radiant heat gain
79
Do football uniforms and equipment present a considerable barrier to heat dissipation during environmental heat exposure?
Yes; even though loose-fitting porous jerseys, wrappings, padding (with plastic covering), helmets, and other objects of "armour" effectively seal off 50% of the body's surface from the benefits of evaporative cooling
80
From a practical standpoint, should children exposed to environmental heat stress exercise at reduced intensity & devote more time to acclimatizing than more mature competitors?
Yes
81
Do Prepubescent children have more heat-activated sweat glands per unit skin area than adolescents and adults, yet sweat less & achieve higher core temperatures during heat stress?
Yes
82
What is Ergogenic (work producing)?
Refers to application of nutritional, physical, mechanical, psychological, physiologic, and pharmacologic procedures or aids to improve physical capacity athletic performance, and responsiveness to training
83
Generally women tolerate the physiological & thermal stress of PA as well as men of comparable fitness & level of acclimatization; both sexes acclimatize to a similar degree. T/F
True
84
Women rely more on circulatory mechanisms for heat dissipation, whereas greater evaporative cooling occurs in men. T/F
True
85
Does excess body fat negatively influence performance in hot environments?
Yes
86
Women possess more heat-activated sweat glands per unit skin area than men, yet they sweat less prolifically. Women begin sweating at higher skin & core temperatures; they also produce less sweat for a similar heat-activity load, even with acclimatization comparable with that of men. T/F
True
87
Do children also take longer to acclimatize to heat than adolescents & young adults?
Yes
88
Does the indiscriminate use of alleged ergogenic substances increase the likelihood of adverse effects that range from relatively benign physical discomfort to life-threatening episodes?
Yes
89
During the 15th century, athletes of the Victorian era routinely used caffeine, alcohol, nitroglycerine, heroin, cocaine, & other stimulants to gain a competitive edge. T/F
True
90
Athletes of Ancient Greece from about 700-3000 B.C. Reportedly used hallucinogenic mushrooms, plant seeds, & ground dog testicles for ergogenic purposes, while Roman gladiator athletes ingested the equivalent of “speed” to enhance performance in the Circus Maximus. T/F
True
91
What does the term 'functional food' mean?
An increasing belief in the potential for selected foods to promote health
92
Why are ergogenic aids complex & controversial and why is there a heightened interest in them?
People want to win
93
What is the process of randomization in research?
When subjects volunteer for an experiment, they must be randomly assigned to either a control or experimental condition
94
Biotechnology also has created the emerging field of transgenic nutraceuticals which is what?
The use of genes introduced into a host plant or animal to modify a biomechanical pathway
95
Do nutraceuticals differ from functional foods that deliver their active ingredients within the food matrix? What are nutraceutical compounds?
Yes; continuum from food to food supplements to drugs
96
What does the term Double Blind in research mean?
The ideal experiment to evaluate the performance-enhancing effects of an exogenous supplement requires that experimental and control subjects remain unaware or "blinded" to the substance administered
97
What does the term Control of extraneous factors in research mean?
Experiences should be as similar as possible for experimental and control groups, except for the treatment variable
98
What are examples of nutraceuticals?
1. Remodeling of cow’s milk by adding or deleting specific milk proteins or adding oligosaccharides
2. Development of novel food oils without requiring chemical hydrogenation & undesirable trans fatty acids
99
What does the term Appropriateness of measurements in research mean?
Reproducible, objective, and valid measurement tools must evaluate research outcomes
100
What does 'Findings should dictate conclusions' mean?
The conclusions of a research study must logically follow from the research findings
101
Companies expend considerable money & effort to show a beneficial effect of a nutritional “aid.” Often a “placebo effect,” a higher level from the suggestive power of believing that a substance or procedure actually works. T/F
True
102
What does 'Baseline nutrition level' mean in research?
Research should establish a subject's nutritional status before experimental treatment
103
What does 'Health status' mean in research?
Nutritional, hormonal, and pharmacologic interventions profoundly affect the diseased and informed, yet offer little or no benefit to those in relatively good health
104
What are substances and methods that are prohibited at all times?
1. Anabolic agents
2. Peptide hormones, growth factors, and related substances and mimetic
3. B2-Agonists
4. Hormone and metabolic modulators
5. Diuretics and masking agents
105
What are the prohibited methods?
1. Manipulation of blood and blood components
2. Chemical and physical manipulation
3. Gene doping
106
What are the 5 areas that work to question the validity of research?
1. Justification (scientific rationale)
2. Subjects (animals or humans, sex, age, training status, baseline nutritional level, health status)
3. Research sample, subjects, & design (random assignment or self-selection, double-blind placebo-controlled experiment, control of extraneous factors, appropriateness of measurements)
4. Conclusions (finding should dictate conclusions, appropriate statistical analysis, statistical vs practical significance)
5. Dissemination of findings (published in peer-reviewed journal)
107
What is scientific rationale?
An experiment based on a specific treatment that should produce a specific effect and will get good results
108
Substances and methods prohibited in competition?
1. Stimulants
2. Narcotics
3. Cannabinoids
4. Glucocorticosteriods
109
Substances prohibited in particular sports?
1. Alcohol
2. B-blockers
110
What is animals or humans for the subject section?
Many diverse mammals exhibit similar physiologic & metabolic dynamics, yet significant interspecies differences exist, which limit generalizations to humans
111
What is the sex section for subjects?
Sex-specific responses to the interactions between PA, training, & nutrient requirements & supplementation limit the generalizability of findings to the sex studied
112
What is the age section for subjects?
Age often interacts to influence experimental treatment outcomes
113
What is training status for the subjects section?
Fitness status & training level influence the effectiveness (or ineffectiveness) of a particular diet or supplement intervention.
114
What is appropriate statistical analysis for a conclusion?
Inferential statistical analysis makes predictions & inferences about a particular population with sample data drawn randomly from the population.
115
What is statistical vs practical significance in your conclusions?
The findings of statistical significance of a particular experimental treatment only means a high probability exists that the results did not occur by chance alone.
116
What does it mean to be published in peer-reviewed journal?
High-quality research withstands the rigors of critical review & evaluation by colleagues with expertise in the specific of investigation. Such peer review provides a measure of quality control over the scholarship & interpretation of research findings.
117
What did the survey done by the NCAA find in regard to supplement use by student athletes?
Creatine was used by 29% of student athletes, amino acids were used by 10% of student athletes, and androstenedione, chromium, and ephedra were each used by about 4% of student athletes
118
What are heat cramps?
Causes: intense, prolonged PA in the heat
S/S: tightening, cramps, involuntary active muscle spasms; low serum Na+
Prevention: cease PA, rehydrate
119
What is heat syncope?
Causes: peripheral vasodilation & pooling of venous blood; hypotension; hypohydration
S/S: lightheadedness; syncope, mostly in upright position during rest or PA; pallor; high rectal temp
Prevention: ensure acclimatization & fluid replenishment; reduce exertion on hot days; avoid standing
120
What is heat exhaustion?
Causes: cumulative negative water balance
S/S: exhaustion; hypohydration, flushed skin; reduced sweating in extreme dehydration syncope, high rectal temp
Prevention: proper hydration before PA & adequate replenishment during PA; ensure acclimatization
121
What is heat stroke?
Causes: extreme hyperthermia leads to thermoregulatory failure; aggravated by dehydration
S/S: medical emergency requiring immediate, emergency, life-saving countermeasures; includes hyperpyrexia (rectal temp >41 deg C, 105.8 deg F); lack of sweating & neurologic deficit (disorientation, twitching, seizures, coma)
Prevention: ensure acclimatization; identify & exclude individuals at risk; adapt activities to climatic constraints
122
What is anabolic steroid use usually combined with?
It is usually combined with resistance training and augmented protein intake to improve strength, speed, and power
123
What 5 mechanisms indicate how food components & pharmacologic agents might enhance exercise performance?
1. Fxn as a CNS or PNS stimulant (caffeine, choline, amphetamines, alcohol)
2. Increase the storage or availability of a limiting substrate (carbs, creatine, carnitine, chromium)
3. Serve as a supplemental fuel source (glucose, medium-chain triacylglycerol)
4. Reduce or neutralize performance-inhibiting metabolic by-products (sodium bicarbonate or citrate, pangamic acid, phosphate)
5. Facilitate recovery (high-glycemic carbs, water)
124
Do 5 million athletes worldwide currently use androgens often combined with stimulants, hormones, & diuretics, believing their use augments training effectiveness?
Yes
125
When and why did Anabolic steroids become available for therapeutic use in oral, injectable, & through-the-skin (transdermal) forms?
They became prominent in the early 1950s to treat patients deficient in natural androgens or with muscle-wasting diseases
126
What is stacking and when do athletes normally use steroids?
Athletes who take steroids do so typically during their active athletic years. They combine multiple steroid preparations in oral & injectable form because they believe various androgens differ in the physiologic action. This practice, called stacking, progressively increases the drug dosage, called pyramiding, usually during 6-12 week cycles
127
What are negative effects on men for using anabolic steroids?
- Testicular shrinkage
- baldness
- increased risk for prostate cancer
- injury & alterations in cardiovascular fxn & myocardial cell cultures
128
Does anabolic steroid use, particularly orally active 17-alkylated androgens, in healthy men and women rapidly reduces high-density lipoprotein cholesterol, elevates both low-density lipoprotein cholesterol and total cholesterol, and reduces the HDL-C-to-LDL-C ratio?
Yes
129
What are the 9 variables that causes confusion about anabolic steroids' ergogenic effectiveness?
1. Experimental design
2. Poor selection of controls
3. Differences in specific drugs
4. Dosages
5. Treatment duration
6. Accompanying nutritional supplementation
7. Training intensity
8. Evaluation techniques
9. Individual differences in response
130
What are negative effects on women for using anabolic steroids?
- virilization
- deepened voice (altered menstrual fxn)
- dramatic increase in sebaceous gland size
- decreased breast size
- possible pathologic ventricular growth & dysfunction when combined with resistance training, increased blood platelet aggregation (impaired cardiac microvascular adaptation to exercise training)
131
What is clenbuterol?
Facilitates responsiveness of adrenergic receptors to circulation epinephrine, norepinephrine, and other adrenergic amines
132
What does hGH do?
hGH stimulates bone and cartilage growth, enhances fatty acid oxidation, and slows glucose and amino acid breakdown, decreases FFM & increases fat mass that accompany aging
133
Why does clenbuterol have particular appeal to female athletes?
It doesn’t produce similar androgenic side effects as do anabolic steroids
134
What does Tetrahydrogestrinone (THG or the Clear) represent?
It represents an anabolic steroid originally designed by an American organic chemist and developed by an American nutritional supplement company to escape detection by standard drug testing
135
A long, steady decline in DHEA occurs after age 30. By age 75, plasma levels decrease to only about 20% of the value in young adulthood. What speculation has this trend fueled?
Fueled speculation that DHEA plasma levels might serve as a biochemical marker or biologic aging and disease susceptibility
136
Have most ergogenic results produced equivocal results during research?
Yes
137
Why was androstenedione banned in 2004 by the FDA?
It’s potent anabolic & androgenic effects
1. No favorable effect on muscle mass, performance, muscle protein synthesis, it tissue anabolism
2. No favorable alterations on body comp
3. Elevates plasma testosterone concentrations & a variety of estrogen
Subfractions
4. Impairs blood lipids d profile in apparently healthy men
5. Increases likelihood of testing positive for steroid use
138
What are the 5 dangers of amphetamine?
1. Continual use can lead to physiologic or emotional drug dependency. This often causes cyclical dependency on "uppers" (amphetamine) or "downers" (barbiturates). Barbiturates blunt or tranquilize the "hyper" state brought on by amphetamines.
2. General side effects include headache, tremulousness, agitation, insomnia, nausea, dizziness, and confusion, all of which impact sports performance
3. Prolonged use eventually requires more of the drug to achieve the same effect because drug tolerance increases; this may aggravate and even precipitate cardiovascular and serious psychologic disorders. Medical risks include hypertension, glucose intolerance, stroke, and sudden death
4. Amphetamines inhibit or suppress the body's normal mechanisms to perceive and respond to pain, fatigue, and heat stress, severely jeopardizing health and safety
5. Prolonged high doses produce weight loss, paranoia, psychosis, repetitive compulsive behaviour, and nerve damage
139
What are amphetamines or “pep pills”?
They are a pharmacologic compounds that exert a powerful stimulating effect on CNS function
140
Why do athletes take amphetamines?
to get “up” psychologically for competition
141
Ironically the majority of research indicates that amphetamines do not enhance various modes of physical performance. T/F
True
142
What amphetamine compounds do athletes most frequently use?
Amphetamine (Benzedrine) & dextroamphetamine sulfate (Dexedrine)
143
When did the Olympics remove caffeine from its list of restrict substances? What were the blood limits?
1. January 2004
2. 12 mL with the NCAA being 15 mL
144
Taking 5-20 mg of amphetamines usually produces an effect that lasts how long?
30-90 minutes
145
Perhaps the greatest influence of amphetamines occurs in the psychological realm, as naive athletes believe that taking any supplement contributes to superior performance. A placebo containing an inert substance often produces results identical to those with amphetamine use. T/F
True
146
How much caffeine is needed to improve performance?
Prior research shows that ingesting 330 mg's of caffeine in 2.5 cups of regular percolated coffee 1 hour before exercising extended intense endurance exercise
147
What are the 3 ways caffeine acts ergogenicly?
1. Directly by stimulating adipose tissues to release fatty acids
2. Indirectly by stimulating the adrenal medulla to release epinephrine; epinephrine then facilitates fatty acid release from adipocytes into plasma. Increased plasma FFA levels increase lipid oxidation, which in turn conserves liver and muscle glycogen.
3. Indirectly produces analgesic central nervous system effects and enhances motorneuronal excitability to facilitate motor unit recruitment
148
Caffeine belongs to a group of methylxanthine compounds that is found naturally in what foods?
Coffee beans
Tea leaves
Chocolate
Cocoa beans
Cola nuts
Added to carbonated beverages
Added to nonprescription medicines
149
Can caffeine directly act on muscle to enhance PA capacity?
Yes
150
What happens to those who normally avoid caffeine when they do drink it?
They may experience undesirable side effects when consuming it.
151
Does caffeine enhance motoneuronal excitability & facilitate motor unit recruitment?
Yes
152
What are the undesirable side affects of caffeine for those who don't regularly consume it?
Restlessness, headaches, insomnia, nervous irritability, muscle twitching, tremulousness, psychomotor agitation, and trigger premature left-ventricular contractions
153
Does caffeine indirectly stimulate the nervous system by blocking another chemical neuromodulator, adenosine, which calms brain & spinal cord neurons?
Yes
154
Is there health risk from regularly consuming coffee?
No, there are no significant health risk with normal caffeine intake, yet death from caffeine overdose has occurred
155
What are four interacting factors produce caffeine’s facilitating effect on neuromuscular activity?
1. Lowered threshold for motor unit recruitment
2. Altered excitation/contraction coupling
3. Facilitated nerve transmission
4. Increased ion transport within the muscle itself
156
What is ginseng root use for in Asian medicine?
Used to prolonged life, strengthen and restore sexual function and invigorating the body
157
Is Ginseng used in the US?
No, ginseng currently serves no recognized medical use in the US except as a soothing agent in skin ointments
158
What does research say about ginseng?
Reports of ginseng's ergogenic possibilities often appear in the lay literature, but a review of the research provides little evidence to support its effectiveness (200 or 400 mg)
159
What are the side effects of taking high ephedrine dosages?
Hypertension, insomnia, hypertermia, cardiac arrhythmias, dizziness, restlessness, anxiety, irritability, personality changes, gastrointensital symptoms, and difficulty concentration
160
The FDA announced a ban on ephedra in April 2004… Was this the first time this federal agency took concrete steps to ban a dietary supplement?
Yes
161
What is alcohol classified as?
Specifically ethyl alcohol or ethanol classifies as a depressant drug. (7kcal/g of energy of pure substance)
162
What does research indicate about alcohol?
Provides no ergogenic benefit; at worst, it hastens undesirable side effects that impair performance
163
The ephedra plant contains 2 major active components first isolated in 1928, ephedrine & pseudoephedrine. The medicinal role of ephedra has included use to treat asthma, symptoms of the common cold, hypotension, urinary incontinence, & as a central stimulant to treat depression. U.S. physicians discontinued using ephedrine as a decongestant & asthma treatment in the 1930s in favor of safer medications. T/F
True
164
Is there any scientific evidence that ginseng supplementation offers and ergogenic benefit to physiological function or physical performance?
No
165
What is bicarbonate used for in the body?
The bicarbonate aspect of the body's buffering system provides a major line of defence against increased intracellular H+ concentration
166
What is glutamine?
Is a nonessential amino acid, provides an anti catabolic effect to enhance protein synthesis
167
One alcoholic drink contains on avg 1oz (28g or 28mL) of 100-proof (50%) alcohol. This translates into 12oz of regular beer (about 4% alcohol by volume) or 5oz of wine (11-14% alcohol by volume). The stomach absorbs between 15-25% of the alcohol ingested. The small intestine takes up the remainder. T/F
True
168
What rate does the liver, the major organ for alcohol metabolism remove alcohol?
10g/hr or equivalent to the alcohol content of 1 drink
169
Does alcohol before competition reduce tension & anxiety, enhance self-confidence, & promote aggressiveness.
Yes
170
Does alcohol facilitate neurological “disinhibition”?
Yes
171
Research doesn’t substantiate any ergogenic effect of alcohol on muscular strength, short-term anaerobic power, or longer-duration aerobic activities. T/F
True
172
Do individuals who bicarbonate-load often experience abdominal cramps & diarrhea about 1 hour following ingestion?
Yes
173
What does glutamine do the body?
Finds that glutamine supplementation effectively counteracts protein breakdown and muscle wasting from related use of exogenous glucocorticoids
174
Does substituting sodium citrate for sodium bicarbonate at a dose of 0.4-0.5g/kg of body mass decrease most adverse GI effects while still preserving ergogenic benefits?
Yes
175
What does research say about pre-exercise glutamine supplement intake?
It has no effect the immune response following repeated bouts of intense activity
176
Does pre-exercise alkalosis benefit low-intensity, aerobic exercise because pH & lactate remain near resting levels?
No
177
Does alcohol exaggerate the dehydrating effect of exercise in a warm environment & act as a powerful diuretic? Do these effects impair thermoregulation during heat stress & place athletes at higher risk for heat injury during physical exertion?
Yes & Yes
178
For bicarbonate-loading are there ergogenic effects that occur for resistance-training exercises?
No
179
Will all-out effort lasting less than 1 minute improve only when performing repetitive exercise with bicarbonate-loading?
Maybe
180
What do the subtle differences in the two PS form do?
May create differences in physiologic action, including the potential for negative effects
181
What is B-hydroxy-B-Methylbutyrate (HMB)?
HMB is a bioactive metabolite generated in breakdown of the essential branched-chain amino acid leucine, decreases protein loss during stress by inhibiting protein catabolism
182
Does all research show beneficial effects of HMB supplementation with resistance training?
No
183
What are the results of HMB supplementation?
It demonstrate an ergogenic effect but it remains unclear just how HMB affects the protein, bone, FFM water component
184
To eliminate the cumbersome & lengthy blood doping process, do endurance athletes now substitute with recombinant epoetin (EPO)?
Yes
185
Unfortunately if self-administered in an unregulated & unmonitored manner (injecting the hormone) hematocrit can increase by more than 60%. Can this dangerously high hemoconcentration & corresponding increase in blood viscosity increase the likelihood of stroke, heart attack, heart failure, & pulmonary edema?
Yes
186
When does glycogen supercompensation occur?
Only in specific muscles depleted by physical activity, so athletes must fully engage the muscles involved in their sport during the depletion phase
187
What is Stage 1 of the dietary plan to increase muscle glycogen storage?
Day 1: Exhausting exercise performed to deplete muscle glycogen in specific muscle
Day 2, 3, 4: Low-Carb food intake
188
What is Stage 2 of the dietary plan to increase muscle glycogen storage?
Day 5,6,7: High-carb food intake
189
What is Competition of the dietary plan to increase muscle glycogen storage?
Follow high-carb precompetition meal
190
The addition of 2.7 grams of water stored with each gram of glycogen makes this a heavy fuel compared with equalivaent energy stored as a lipid? -T/F
True
191
Do the potential benefits from carbs loading apply only to intense & prolonged aerobic activities?
Yes
192
What is hitting the wall or bonking?
Used to describe sensations of fatigue & discomfort in the active muscles associated with severe glycogen depletion.
193
What are factors for race success?
include muscle mass distribution (large leg muscles), high liver & muscle glycogen densities, running speed as a high percentage of aerobic capacity, & low oxygen cost of running at a particular speed (high economy of effort)
194
What does research on healthy subjects not provide concrete evidence for?
Ergogenic effects of a general dietary increase of oral amino acid supplements on hormone secretion, training responsiveness or physical performance
195
What are branched-chain amino acids (BCAA)?
Claims: stimulates protein synthesis to spare muscle
Effectiveness: moderate to high
Concerns: Safe
196
What do studies of hormonal dynamics and protein anabolism indicate?
Indicates a transient but potential fourfold increase in protein synthesis with carb or protein supplements (or both) consumed immediately following resistance exercise workouts
197
What is casein protein?
Claims: helps decrease protein breakdown; increases protein synthesis
Effectiveness: moderate to high
Concerns: may increase blood cholesterol
198
What do beneficial effects of chromium supplements on body fat and muscle mass incorrectly infer?
It incorrectly infers body composition changes from changes in body weight or anthropometric measurements instead of the more appropriate valid assessment methods
199
What is glutamine?
Claims: involved in energy metabolism to spare protein breakdown
Effectiveness: high
Concerns: requires high doses; safe
200
What is Leucine?
Claims: helps spare muscle tissue
Effectiveness: moderate
Concerns: safe
201
What is whey protein?
Claims: source of essential amino acids; decreases protein catabolism, spares protein
Effectiveness: high
Concerns: safe
202
What are theta-ketogluterates?
Claims: spares glutamine (thus sparing muscle tissue), the largest source of the body’s glutamine
Effectiveness: moderate to high
Concerns: well tolerated, but long-term safety unclear
203
What is chromium touted as?
A fat burner and muscle builder
204
What does chronic chromium deficiency do?
Increases blood cholesterol and decreases sensitivity to insulin, thus increase the chance for developing Type 2 Diabetes
205
What does chromium compete with in the body?
It competes with iron for binding to transferrin, a plasma protein that transports iron from ingested food and damaged red blood cells and delivers it to tissues in need
206
What increases the potential for chromium deficiency?
Processing also removes considerable chromium from foods, & strenuous PA & associated high carb intake promote urinary chromium losses
207
Why do marketers of L-carnitine target endurance athletes?
It appeals to them because this “metabolic stimulator” enhances lipid burning & spares glycogen.
208
What other athlete group finds appeal in L-carnitine?
It also appeals to bodybuilders as a practical but unproven enticement to reduce body fat
209
Where is Coenzyme Q10 found?
meats, peanuts, and soybean oil (functions as an integral component of mitochondrion’s electron transport system of oxidative phosphorylation)
210
How has Coenzyme Q10 been used to therapeutically for treatment?
Treat cardiovascular disease because of its role in oxidative metabolism & antioxidant properties (promote free radical scavenging that damage cellular components)
211
Does taking Coenzyme Q10 give a benefit?
No, there is no benefit found in taking it on a regular basis.
212
What has the federal trade commission ordered manufacturers of chromium supplements to cease doing?
promoting unsubstantiated weight loss & health claims (reduced body fat, increased muscle mass, increased energy) for chromium picolinate. Companies can no longer claim benefits for this compound unless reliable research data substantiates such claims.
213
What is a "loading" phase of creatine?
It calls for ingesting 20-30 grams of creatine daily for 5-7 days as a tablet or powder added to liquid
214
Does caffeine negates the ergogenic effects of creatine supplementation?
Yes
215
What are 3 ergogenic effects that should happen with an increase in intramuscular creatine (PCr)?
1. Improve repetitive performance in muscular strength & short-term power activities
2. Augment short bursts of muscular endurance
3. Provide greater muscular overload to enhance resistance-training effectiveness
216
Consuming creatine with a sugar-containing drink increases creatine uptake & skeletal muscle storage. What amt did subjects receive?
For 5 days subjects received either 5g of creatine supplement 4x/day (creatine increased 7.2%, 13.5%, 20.7%) or 5g supplement followed 30 minutes later by 93g sugar loading drink 4x/day (creatine increased 14.7%, 18.1%, 33%)
217
What are 2 potential unintended consequences of creatine supplementation?
1. Altered intracellular dynamics from increased free creatine & PCr levels
2. Osmotically induced enlarged muscle cell volume caused by increased creatine content
218
Meat, poultry, & fish provide rich creatine sources, containing approximately 4-5 grams per kg of food weight. T/F
True
219
What are Short-chain fatty acids (SCFAs)?
<6 carbons
220
What are Medium-chain fatty acids (MCFAs or MCT)?
6-12 carbons
221
Does objective data support an ergogenic role for inosine supplementation?
No
222
What are Long-chain fatty acids (LCFAs)?
13-21 carbons
223
What are Very Long-chain fatty acids (VLCFAs)?
>22 carbons
224
Does research support an ergogenic role for vanadium supplements?
No, individuals should not supplement with this element because an extreme excess of vanadium becomes toxic to the liver.
225
Do these findings alone contraindicate any use of inosine supplements for possible ergogenic effects?
Yes
226
What are vanadium's toxic effects?
Local eye irritation, and upper respiratory tract rather than systemic toxicity
227
In general do the relatively small alterations in substrate availability & substrate oxidation by increasing FFA availability during moderately intense aerobic activity have only a negligible ergogenic effect on performance capacity?
Yes
228
What is vanadium?
A trace element widely distributed in nature
229
Should coaches, trainers, and athletes remain skeptical about the effectiveness of pyruvate supplementation in general and the general lose of body fat?
Yes
230
What are the undesirable side effects of exogenous glycerol ingestion?
Nausea, dizziness, bloating, and light-headedness.
231
Why is glycerol supplementation not banned?
Because proponents argue that a ban on glycerol use only increases heat injury risk to elite athletes, including potentially fatal heat stroke
232
Why did glycerol achieve clinical notoriety?
The two-carbon glycerol molecule achieved clinical notoriety along with mannitol, sorbitol, & urea for helping to produce an osmotic diuretics (increased urination)
233
What are the 4 important roles that glycerol plays in body function & structure?
1. Triacylglycerol molecule component
2. Gluconeogenic substrate
3. Constituent of the cells phospholipid plasma membrane
4. Osmotically active natural metabolite
234
Figure 10.1; What are the ten contributing factors to heat gain and heat loss to regulate core temperature at about 37C (98.6F)?
Heat loss- radiation, convection, conduction, evaporation
Heat gain- BMR, muscular activity, hormones, thermic effect of food, postural changes, environment
