Exam 4 Flashcards
(50 cards)
1
Q
what is WBGT
A
- wet bulb globe temp
- accounts for conduction, convection, evaporation, radiation
- better tool to evaluate level of environmental stress during exercise
2
Q
how is a sling psychrometer used to measure wet bulb globe temp (WBGT)
A
- wbgt = 0.1Tdb + 0.7Twb + 0.2*Tg
- wet bulb, dry bulb, globe
- use sling psychometer to measure Tdb & Twb (Tg = Tdb)
3
Q
what are the different heat illnesses
A
- heat cramps: caused by loss of sodium & dehydration (due to hugh sweat rates) or accumulation of fluid in muscle cells (lactate draws water into muscle) or both; most common in heavy sweaters who are poor sodium conservers; proper hydration, liberal salt intake with food & in bevs consumed during exercise
- heat exhaustion: diziness, fatigue, nausea, vomiting, fainting, weak & rapid pulse, pale & cool skin, Tcore < 39 degrees c, cant dissipate heat quick enough because insufficient blood volume is available to allow blood flow to skin, unfit or unacclimated people are most susceptible, Tx: rest in cooler environment with feet elevated, salt water ingestion, iv admin of saline solution
- heat stroke: life threatening, Tcore > 40 deg c, altered mental status, cessation of active sweating, whole body immersion, teperate water immersion, wrapping entire body in cold, wet sheets, vigorous fanning
4
Q
what heat illnesses are life threatening
A
heat stroke
5
Q
what heat illnesses are the least severe
A
heat cramps
6
Q
what are the ways body heat is transferred to/from the body
A
- conduction: direct molecular contact with object
- convection: motion of gas or liquid across heated surface
- radiation: infrared rays (at rest 60% of excess heat is lost through radiation, exercise heat loss via radiation 5%)
- evaporation: primary avenue for heat dissipation during exercise, when air temp is close to skin temp evap is only way of cooling, accounts for ~80% total heat loss during evap, 10-20% heat loss at rest, heat loss not gain
7
Q
what is the main avenue for heat dissipation at rest
A
radiation
8
Q
what is the main avenue for heat dissipation at exercise
A
evaporation
9
Q
what is the most effective way to cool a person who has a heat stroke
A
whole body immersion
10
Q
what is the difference between hypohydration & dehydration
A
- hypohydration: decrease in PV only, state of insufficient body water, body is below normal hydration level
- dehydration: decrease in PV & increase in osmolality, losing water leading to a water deficit
11
Q
what are ways humans adapt/acclimate to the heat? which adaptation occurs the soonest?
A
plasma volume increases, heart rate decreases, earlier sweat onset, decrease in perceived exertion, decrease NaCl sweat, increasing sweat rate, decrease T core
- earliest: early onset of sweating which leads to increased PV & reduced HR
12
Q
what is pokilothermic
A
- 30 C (86 F): shivering ceases & body becomes poikilothermic (passively cools to Ta)
- homeostasis body reg of internal temp
13
Q
how does age affect our ability to thermoregulate
A
- reduces simulated body fluid (SBF) & degree of vasoconstriction in response to cold air exposure
- possible that blood vessels cant maintain constrictor tone effectively
14
Q
as humans, how do we adapt to the cold? what is the difference between the way we adapt vs the way Ama divers adapt to the cold?
A
- habituation: blunted, less vigorous shivering in response to Ta
- metabolic pattern: less observed than habituation, greater heat production, more pronounced shivering & non shivering thermogenesis in cold
- insulation pattern: less observed than habituation, augmentation of VC responses in skin & superficial muscles, may involve increased fat thickness in subcutaneous tissues
- conserve E rather than conserve heat
- ama:
> insulative: better better VC
> metabolic (increased BMR)
> habituation: increased tolerance to cold (less shivering, later onset of shivering)
15
Q
what is the main substrate we rely on in cold environments? why?
A
fats because we rely on thermogenesis which burns fat to create heat
16
Q
what effect does ascent to altitude have on the hemoglobin-O2 dissociation curve
A
leftward shift causes hemoglobin binds oxygen at a partial pressure less oxygen delivery at tissue level
17
Q
what are the different altitude illnesses
A
- acute altitude mountain sickness: low ventilatory response to altitude, co2 accumulates, acidosis, mostly experienced >3600 m, continous & throbbing, hypoxia > cerebral vasodilation > stretch pain receptors
- altitude sickness insomnia: interruption of sleep stages due to hypoxia
18
Q
what are the renal, respiratory, CV, and metabolic responses to altitude
A
- kidneys excrete more bicarbonate to increase pH
- pulmonary ventilation increases immediately
- ventilation at altitude = hyperventilation
- respiratory alkalosis = high blood pH
19
Q
what are the differences between the physiology of highlands & lowlanders when residing at altitude
A
- larger heart dimensions
- greater cardiac muscle mass
- larger lungs
- more capillaries
- smaller body size with larger chest (larger lung capacity for smaller body)
- more coronary artery circulation = greater capacity for o2 diffusion across lungs capillaries
20
Q
what is lactate paradox`
A
- inc in anaerobic metabolism = inc in lactic acid
- lactic acid production decreases over time
- no explanation
21
Q
what is hypocapnia
A
condition with a reduced amount of carbon dioxide in blood (usually below 35 mmHg)
22
Q
what effect does ascent to high altitude have on vo2max
A
- decreases as altitude increases past 1500 m
- lowers because HR decreases and less o2 to breathe
23
Q
how does altitude affect aerobic performance
A
- declines
- low alt (may be decreased, restored by acclimation)
- moderate alt: performance and aerobic capacity decline, may or may not be restored by acclimation
- 1500 m difference produced 7% impairment in repeat spring performances
- high alt: performance declines, not restored by acclimation
- few if any physiological effects <1500 m
24
Q
how does altitude affect anaerobic performance
A
- unaffected
- minimal o2 requirements
- ATP-PCr & anaerobic glycolytic metabolism
25
how long does acclimatization to altitude take
- 3 weeks (2-4) at moderate altitude
- add 1 week for every additional 600 m
- lost within 1 month at sea level
- immediate responses within minutes to hours: increased ventilation and HR
26
what would happen to the physiological adaptations to altitude once a person returns to sea level? how soon do these changes occur?
- adaptations such as increased ventilation & hematocrit reverse over days to weeks
- most changes normalizing within 2-4 weeks
- occur because body no longer needs to compensate for reduced oxygen availability
27
what are the different ways we measure body comp? assumptions & limitations of each?
- anthropometry (assumptions: circumferences are affected by FM, muscle mass & skeletal size so they reflect both fat & FFM, skeletal diameters & circumference measures are strong markers of LBM)
- BMI
- waist to hip ratio
- UWW
- skinfolds
28
what is the difference between fat free mass & lean body mass
- FFM: composed of all the body's nonfat tissue including bone, muscle, organs & connective tissue
- lean body mass: includes all fat free mass along with essential fat (difficult to measure)
29
what are the normal/healthy waist circumference norms for females & males
- increased risk for coronary heart disease & metabolic diseases:
females: WC>88 cm
males: WC>102 cm
30
what is the equation to determine BMI? what are the normative ranges?
- weight in kg/height in m^2
- obese > 30 kg/m2
- overweight > 25 kg/m2
- underweight < 18.5 kg/m2
31
what is the equation used to determine body density
- body density = body mass/body volume
- body mass measured on land
- body volume = difference between athletes weight on land & UWW (measured using UWW accounting for water density & air trapped in lungs)
32
what are the 3 skinfolds used to measure body fat in males? females?
- males: chest, abdomen, thigh
- females: triceps, suprailiac, thigh
33
what are the minimum, healthy body fat percentages for 20-some year old males? females?
- males (7-17) 5% +-2
- females (16-24) 10% +- 2
34
what is glycemic index? what are the ranges of low and high GI
- CHO quality
- all foods scored relative to thIS GI (50g of food over 2 hrs)
- high GI: GI >70
- moderate GI: GI = 56-70
- low GI: GI<56
- GI index = blood glucose response over two hours to 50 g of test food/blood glucose response over two hours to 50 g of glucose
35
what type of food should be consumed to maximize performance prior to exercise? during exercise?
- 30 min or greater before/ immediately prior to exercise = low GI food
- during exercise = high GI food
36
what is the amount of carbohydrate (percentage of diet) that should be contained in an endurance athlete's diet?
- 50% most athletes
- 55-65% endurance athletes
36
what is the amount of CHO that should be contained in a rehydration bev? why is there an optimal amount of CHO for rehydration drinks? when should these bevs be used?
- 6-11%
- too much CHO decrease mobility
- > 60 min
37
what is the amount of protein (percentage of diet) that should be contained in an endurance athlete's diet?
1.2 - 1.4 g/kg
38
which type of protein has research shown to have the greatest impact on muscle repair
whey protein
39
what are the RDA for protein for children? endurance athletes? strength athletes? nonexercised adult ?
- children (4-13): 0.95 g/kg
- children (14-18): 0.85 g/kg
- adults: 0.8 g/kg
40
dehydration by what amount (as a % of body weight) would hinder performance? what type of performance would be hindered by dehydration?
- 2%
- endurance
- strength & power may or may not be affected
41
what is CHO loading? what are the benefits? drawbacks?
- carboloading
- increases the amount of glycogen in muscles which can determine endurance time
- benefits: increase muscle glycogen by 2-3x, increase endurance capacity, increase sprinting ability at the end of prolonged activity
- drawbacks: increase in body mass (stiff/heavy), high CHO diet is detrimental to a diabetic individual, detraining effect
42
how is thirst stimulated?
- increase in sodium content
- sensed by osmoreceptors in hypothalamus
- Sensory signals of thirst invoke when plasma osmolality is increased above threshold
- Second set of signal arise from low pressure pressure baroreceptors
43
what is the female athlete triad?
- A medical condition that occurs when a female athlete has a chronic energy deficit which can lead to disordered eating, irregular or miss periods and low bone density
44
what is iron deficiency? how would this affect exercise performance?
-
- iron/heme = hemoblobin (o2 carrying molecule)
- ETC > cytochrome complex > ability to use ETC reduced
45
what is the vitamin B complex used for in metabolism
- B1 - thiamin: conversion of pyruvic acid to acetyl coA (1st step leading into krebs)
- B2 - riboflavin: (FAD, flavin adenin dinucleotide, aka coenzyme in krebs)
- B3 - niacin (NAPD - nicotinamide adnine dinucleotide phase, coenzyme in glycolysis)
- B12 - cyanocobalamin: needed for RBC production
46
what are the positive & negative factors for coronary artery disease?
47
what steps/forms would be approporiate for you to use when working with a new client
48
review the training principles
49
how is target heart rate calculate (using the karvonen formula)
