What glands release hormones directly into the blood?
What alters the activity of tissues that possess receptors to which it can bind?
What determines the magnitude of the effect at the tissue level?
Plasma hormone concentration
Rate of insulin secretion by the pancreas is dependent on what? (2)
Magnitude of input | Stimulatory or inhibitory factors
Hormone receptor interactions: the magnitude of effect depends on what? (3)
Concentration of hormone | Number of receptors on the cell | Affinity of receptor hormone
Hormone receptor interactions: in what ways do hormones bring about effects? (3)
Altering membrane transport | Stimulating DNA to increase protein synthesis | Activating second messengers (Cyclic AMP/Calcium)
Identify 4 factors that influence the concentration of a hormone in the blood.
Rate of secretion of hormone from endocrine gland | Rate of metabolism | Quantity of transport protein | Changes in plasma volume
What could cause plasma volume to decrease?
How does a steroid hormone act on a cell?
Attach to cells receptor site | Hormone/receptor complex moves into the cell | Attaches to gene in nucleus | Stimulates protein synthesis
What are molecules that relay the signals of hormones like epinephrine (adrenalin), growth factors, and others, and cause some kind of change in the activity of the cell? | They greatly amplify the strength of the signal.
____ is a second messenger, used for intracellular signal transduction, such as transferring the effects of hormones like glucagon and adrenaline, which cannot pass through the cell membrane | It is involved in the activation of protein kinases and regulates the effects of adrenaline and glucagon | It also regulates the passage of Ca2+ through ion channels
What controls activity of the anterior and posterior pituitary glands (influenced by positive and negative input)?
____ are any of several hormones produced in the hypothalamus and carried by a vein to the anterior pituitary gland where they stimulate the release of anterior pituitary hormones; each of these hormones causes the anterior pituitary to secrete a specific hormone.
Hypothalamic releasing factor
Hormones are secreted from what?
Epinephrine: What is the release site/release stimulus/predominate action for this hormone?
Adrenal Medulla | Increases: HR, glycogenolysis, and lipolysis
Norepinephrine: What is the release site/release stimulus/predominate action for this hormone?
Adrenal Medulla | Increases: HR, glycogenolysis, and lipolysis
Glucagon: What is the release site/release stimulus/predominate action for this hormone?
Pancreas | Promotes the mobilization of fatty acids and glucose
Insulin: What is the release site/release stimulus/predominate action for this hormone?
Pancreas | Promotes the storage of glucose, amino acids, and fats
Cortisol: What is the release site/release stimulus/predominate action for this hormone?
Adrenal Cortex | Long-term exercise and fasting | Promotes the use of free fatty acids as fuel; Stimulates glucose synthesis; * Promotes protein breakdown for gluconeogenesis and tissue repair
Aldosterone: What is the release site/release stimulus/predominate action for this hormone?
Adrenal Cortex | Change in aldosterone during exercise | Maintains plasma Na+ and K+; Regulates blood pressure
Antidiuretic Hormone (ADH): What is the release site/release stimulus/predominate action for this hormone?
Posterior Pituitary Gland | High plasma osmolality; Low plasma volume (due to sweating); * Exercise (increases significantly at 60% VO2) | Reduces water loss from body to maintain plasma volume
Thyroxine (T4): What is the release site/release stimulus/predominate action for this hormone?
Thyroid Gland | Maintains metabolic rate
Growth Hormone: What is the release site/release stimulus/predominate action for this hormone?
Anterior Pituitary Gland | Increases during exercise: Mobilizes fatty acids from adipose tissue; Aids in the maintenance of blood glucose | Essential for normal growth: * Stimulates protein synthesis and long bone growth
Estrogen: What is the release site/release stimulus/predominate action for this hormone?
Ovaries | Establish and maintain reproductive function; Estrogen levels vary throughout the menstrual cycle
Testosterone: What is the release site/release stimulus/predominate action for this hormone?
What are the fast acting hormones of the maintenance of plasma glucose during exercise? (4)
Norepinephrine and epinephrine | Insulin and glucagon
What actions do the fast acting hormones of the maintenance of plasma glucose during exercise produce? (3)
Glycogenolysis and gluconeogenesis | Mobilization of free fatty acids from adipose tissue
What does the mobilization of free fatty acids from adipose tissue do? (3)
Increases use of FFA as a fuel | Blocks entry of glucose into cells | Spares blood glucose
What are the permissive and slowly acting hormones of the maintenance of plasma glucose during exercise? (2)
Cortisol | Growth hormone
What action does the permissive and slowly acting hormones of the maintenance of plasma glucose during exercise produce? (1)
Act in a permissive manner to support actions of other hormones
What role do catecholamines have in substrate mobilization?
What happens to epinephrine and norepinephrine during exercise? (2)
Increases linearly during exercise | Favor the mobilization of free fatty acids and maintenance of plasma glucose
What happens to epinephrine and norepinephrine following exercise? (2)
Decrease in plasma levels | Parallel reduction in glucose mobilization
What is our "fed" hormone that promotes the uptake, and storage of glucose, amino acids and what does "fed" mean?
Insulin | Increases with a meal high in starch/glucose and/or amino acids
Glucagon release is stimulated by what? (2)
Low blood sugar (glucose) | Exercise
Glucagon mobilizes energy stores by doing what? (2)
Promoting breakdown of triglycerides to glycerol and free fatty acids in adipose cells, into blood | Stimulates liver to produce glucose
Glucagon stimulates the liver to produce glucose by way of what? (2)
Glycogenolysis | Gluconeogenesis
What happens to insulin during exercise? (3)
Plasma insulin decreases during exercise (up to 60-70% VO2 max) | Prevents rapid uptake of plasma glucose by non-contracting muscles | Favors mobilization of liver glucose and lipid free fatty acids
What happens to insulin in trained subjects during exercise? (2)
Much faster decrease in plasma insulin | Increase in plasma glucagon
What are the effects of cortisol? (3)
Stimulates free fatty acid mobilization from adipose tissue | Mobilizes amino acids for gluconeogenesis | Blocks entry of glucose into cells
Plasma Cortisol (during exercise): | Low intensity = ____ in plasma cortisol | High intensity = ____ in plasma cortisol | Switchover occurs at about ____% VO2 max
Low intensity = decrease in plasma cortisol | High intensity = increase in plasma cortisol | Switchover occurs at about 60% VO2 max
Growth hormone increases ____ during exercise?
What hormone, during exercise, is important in the maintenance of blood glucose?
During exercise, growth hormone does what in the maintenance of blood glucose? (3)
Decreases glucose uptake | Increases free fatty acid mobilization | Enhances livers production of glucose (gluconeogenesis)
Graphically describe the changes in the following hormones during graded exercise: insulin, glucagon, cortisol, growth hormone, epinephrine, and norepinephrine.
Graphically describe the changes in the following hormones during prolonged exercise: insulin, glucagon, cortisol, growth hormone, epinephrine, and norepinephrine.
Effect of Exercise Intensity on Fatty Acid Mobilization: | During ____ exercise: fatty acid mobilization = utilization
Effect of Exercise Intensity on Fatty Acid Mobilization: | During ____ exercise: fatty acid mobilization < utilization initially, so plasma concentration initially goes down, but over time fatty acid mobilization becomes > utilization
Effect of Exercise Intensity on Fatty Acid Mobilization: | During ____ exercise: fatty acid mobilization << utilization
What is an organism called that maintains its body temperature at a constant level, usually above that of the environment, by its metabolic activity?
Heat balance: in order to maintain a constant temperature what must happen?
Heat loss must equal heat gain
Where does heat gain mostly come from?
What are the principle means of involuntary heat production?
Shivering | Action of hormones (Thyroxine (T4) and Catecholamines)
What is the transfer of heat via infrared rays where there is no physical contact between surfaces and 60% of heat loss occurs at rest defined as? (Small roll in heat loss during exercise)
What is heat loss due to contact with another surface defined as?
What is a form of conductive heat loss whereby heat is transferred to air or water? (Small contribution to heat loss during exercise, but is increased with cycling or swimming)
What is heat transferred via water (sweat) on the skins surface and makes up 25% of heat loss at rest defined as? (Most important means of heat loss during exercise)
What is the body's "thermostat"?
What is stimulated and what happens when the body's core temperature increases? (1) (2)
Anterior hypothalamus is stimulated | Commencement of sweating | Increased skin blood flow
What is stimulated and what happens when the body is exposed to cold? (1) (2)
Posterior hypothalamus is stimulated | Increased heat production (shivering) | Decreased skin blood flow
What happens as ambient temperature increases? (3)
Heat production remains constant | Decreased convection and radiant heat loss | Increased evaporation
The production of what stimulates heat loss?
Metabolic energy (heat)
List the heat loss types in order from most important to least important. (3)
Evaporative, Convection, Radiative
The increase in body temperature with work rate is a ____ relationship.
In regards to the body's temperature increase during exercise, temperature is proportionate to ____ muscle mass.
With increased exercise intensity, what happens to heat production? (1) Convective and radiant heat loss? (1) Evaporative heat loss? (1)
Heat production increases | Lower convective and radiant | Higher evaporative
What happens when exercising in hot humid environments? (2)
Inability to lose heat (higher core temp, higher sweat rate)
What can result if you are unable to lose heat? (2)
Impaired performance | Hyperthermia
What physiological adaptations occur during acclimatization to heat? (5)
Increased plasma volume (most important) | Earlier onset of sweating | Higher sweat rate | Reduced sodium chloride loss in sweat | Reduced skin blood flow
How many days does heat acclimatization take to occur?
What is the physiological response to a cold environment and what could this result in? (2)
Enhanced heat loss | May result in hypothermia
What physiological adaptations occur during cold acclimatization? (3)
Improved ability to sleep in the cold | Increased non-shivering thermogenesis | Higher intermittent blood flow to hands and feet
What happens to atmospheric pressure at higher altitudes?
Define: Hypoxia, Normoxia, and Hyperoxia.
Hypoxia: Low PO2 (altitude) | Normoxia: Normal (Sea Level) | Hyperoxia: High PO2
What effect does lower PO2 at altitude have on short-term anaerobic performance?
What effect does lower air resistance have on short-term anaerobic performance?
May improve performance
What effect does lower PO2 have on long-term aerobic performance?
Poorer aerobic performance
What happens to plasma volume initially at altitude?
Decreases (more red blood cells per unit of blood, thus more oxygen per unit of blood)
What happens to heart rate and cardiac output initially during submaximal work to compensate for less oxygen?
What happens during maximal work that limits oxygen delivery and uptake at altitude?
HR, SV and Q decrease
Cardiovascular Responses to Altitude: Shifts in Hb-O2 dissociation curve to the ____.
What happens to anaerobic metabolism at altitude?
What happens to lactic acid production at altitude?
Is there more or less lactic acid production at maximal work rates at altitude than at sea level?
Effect of altitude on VO2 max: What is the decreased VO2 max due to at higher altitudes?
Decreased arterial PO2 | Decreased cardiac output
What happens to ventilation at submaximal exercise at altitude? What happens to heart rate?
Higher heart rate | Higher ventilation
Why does ventilation increase at altitude?
Fewer O2 molecules per liter of air
What senses the decrease in PaO2?
What is the hypoxic ventilatory response (HVR)?
Increase in ventilation induced by hypoxia
If you are less sensitive to HVR, what do you have a higher chance of?
How does our bodies adapt to higher altitude? | ____ in number of red blood cells, hemoglobin, and blood viscosity | Short-term ____ in plasma volume (later reversed) | ____ in muscle fiber areas and total muscle area | ____ in capillary density | ____ in pulmonary ventilation | ____ in VO2 max with initial exposure (does not change much after initial change)
Increase in number of red blood cells, hemoglobin, and blood viscosity | Short-term decrease in plasma volume (later reversed) | Decrease in muscle fiber areas and total muscle area | Increase in capillary density | Increase in pulmonary ventilation | Decrease in VO2 max with initial exposure (does not improve much)
Acclimatization (Adaptation) to Altitude: Shift in the Hb-O2 dissociation curve to the ____.
Do people who grow up at altitude have complete adaptations in arterial O2 contents and VO2 max? What about those new to altitude?
Yes | People who are new to altitude have adaptations that are less complete
Changes in Muscle Structure: Both oxidative and glycolytic enzymes are ____ with chronic hypoxia.
Why does the effect of training at altitude on VO2 max vary among athletes?
Due to degree of saturation of hemoglobin
Who shows the greatest decrease of VO2 max at altitude?
Athletes with the highest VO2 max at sea level
What happens to red cell mass on return to sea level?
Does altitude training improve sea level performance?
Not proven that altitude training improves sea-level performance | Difficult to study since intensity and volume are reduced at altitude
Does "living high/training low" really work?
Doesn't really work and is difficult to do
What can you do to train for optimum altitude performance? (3)
Compete within 24 hours of arrival | Train at altitude for 2 weeks before competing | Increase VO2 max at sea level
Can you train as intensely at high altitude?
Explain the role that hyperventilation plays in helping to maintain a high oxygen-hemoglobin saturation at extreme altitudes. (2)
Drives down PCO2 and H+ in blood | Allows more O2 to bind with hemoglobin at same PO2
Occurs when a system is exercised at a level beyond which it is normally accustomed.
What is the training effect that is specific to the muscle fibers involved (type of exercise) defined as?
Gains that are lost when overload is removed is defined as what?
____ studies examine groups of differing physical activity at one time. (Record differences between groups)
____ studies- examine groups before and after training (Record changes over time in the groups)
What are the expected changes in VO2 max with endurance training programs? What population type has the greater increase?
15% (average) - 40% (strenuous or prolonged activity) | Greater increase in highly deconditioned or diseased subjects
Genetic disposition accounts for ____% of VO2 max.
State the VO2 max values for diseased, sedentary, active and athletic populations.
What are the changes in muscle structure that are responsible for the increase in the maximal a-vO2 difference with endurance training? (3)
Increased muscle blood flow | Increased capillary density | Increased mitochondrial number
What are the changes in blood components that are responsible for the increase in the maximal a-vO2 difference with endurance training? (4)
Increased total blood volume | Increased plasma volume | Increased red cell mass | Decreased consequence on blood viscosity
What are the underlying causes for the decrease in VO2 max that occurs with cessation of endurance training? (2)
Decreased SV max | Decreased maximal a-vO2 difference
About ____% of the increase in mitochondrial content was lost after 1 week of detraining | All of the adaptations were lost after ____ weeks | It took ____ weeks of retraining to regain the adaptations lost in the first week of detraining
50% | 5 weeks | 4 weeks
What is the maker of mitochondrial oxidative capacity?
Citrate synthase (CS)
What types of fibers have the same response at any intensity and duration for mitochondrial enzymes?
Type IIA (red gastrocnemius)
What type of muscle fiber increases mitochondrial enzymes with increased intensity and duration?
Type IIb (white gastrocnemius)
Light to moderate exercise training = increased CS in ____ oxidative fibers while strenuous exercise training = increased CS in ____ oxidative fibers.
High | Low
What stimulates mitochondrial ATP production?
Are less [ADP] needed to increase ATP production and VO2 (oxygen uptake)? (Meaning you can make some ATP with less [ADP])
After endurance training oxygen uptake kinetics are ____, while the O2 deficit is ____.
Faster | Lower
In regards to biochemical adaptations and FFA oxidation; | ____ mitochondrial number and capillary density | ____ enzymes of b-oxidation | ____ FFA oxidation
Increased mitochondrial number and capillary density | Increased enzymes of b-oxidation | Increased FFA oxidation
In regards to the endurance training crossover concept, what happens and what is the net result? (4)
Increased FFA oxidation | Spares muscle glycogen | Spares blood glucose | Net result: shifts crossover curve to the right
What is blood lactate a balance between?
Lactate production/appearance in blood and removal/disappearance from blood (Ra ->blood lactate -> Rd)
Endurance training shifts the lactate threshold to the ____.
What does strength training result in? (2)
Increase muscle size and strength | Increased ability to activate motor units
Why is there a great initial gain in the first 4-6 weeks of strength training?
Motor units are more active
What is muscular enlargement due to?
Hypertrophy | Long term strength training
What are factors that can affect maximal performance? (6)
Energy Production (Anaerobic Sources) | Energy Production (Aerobic Sources) | Diet | CNS Function | Strength/Skill | Environment
What are the sites of fatigue? (2)
Central fatigue | Peripheral fatigue
How can the central nervous system arousal alter the state of fatigue? (1)
By facilitating motor unit recruitment
Repeated stimulation of the sarcolemma can do what? (2)
Reduce size and frequency of action potentials
A block of the action potential in the T-tubules will cause a reduction in ____ release from the sarcoplasmic reticulum.
What are the mechanical factors of peripheral fatigue? (4)
Reduction in force per cross-bridge | Reduction of force generated at a given Ca2+ concentration | Inhibition of Ca2+ release from sarcoplasmic reticulum | Lack of ATP to dissociate the cross-bridge from actin
Fatigue results in the slowing of ATP utilization to preserve what? (1)
List the muscle fiber recruitment in increasing intensities of exercise. (3)
Type I, Type IIa, Type IIb (Type IIx)
The progression from most to least oxidative fiber types being recruited with increasing intensities of exercise results in what? (1)
Increased lactate production
What is ultra-short-term performance (less than ten seconds) dependent on? (1)
Recruitment of Type II muscle fibers
What are the primary energy sources for anaerobic exercise? (2)
Phosphocreatine | Some anaerobic glycolysis
What are characteristics of the metabolism shift (classification/percent) when performing short term exercise (10 - 180 seconds)? (2)
Shifts from entirely anaerobic towards aerobic metabolism | 70% anaerobically at 10 seconds to 60% aerobic at 180 seconds
What are the primary energy sources for short term performance (10-180 seconds)? (2)
Anaerobic Glycolysis | Some aerobic metabolism
Moderate Length Performance (3-20 minutes): How is ATP generated early on at 3 minutes? Later around 20 minutes?
[Start to see more and more ATP generated aerobically!] | 60% of ATP generated aerobically at 3 minutes | 90% of ATP generated aerobically at 20 minutes
How is energy supplied in intermediate length performances (21-60 minutes)? (1)
Intermediate length performances (21-60 minutes) are usually performed at ____% of VO2 max.
What are environmental factors that are important in intermediate length performances (21-60 minutes)? (3)
Heat | Humidity | Hydration
What maintains the rate of carbohydrate utilization during long term performance (1-4+ hours)? (2)
Muscle and liver glycogen
What are the training methods to increase aerobic power? (3)
Interval training | Long, slow distance | High intensity, continuous exercise
What appears to be the most important factor for improving VO2 max?
What is interval training?
Repeated exercise bouts separated by rest periods at 85-100% VO2 max
How long should interval training last to improve VO2 max?
Longer than 60 seconds
What is long, slow distance exercise?
Long-intensity exercise (50-60% VO2 max or 70% HR max) with duration greater than what would be expected in competition
What concept is long slow distance training based on?
Volume of training
What is the best method of exercise for increasing VO2 max and the lactate threshold?
High intensity, continuous exercise
What is high intensity, continuous exercise?
High-intensity exercise (80-90% HR max) at or above lactate threshold, with duration of 25-50 minutes (depending on individual fitness level)
What are most injuries the result of?
Intensity and duration of exercise should not be increased by what?
More than 10% a week ("10 percent rule")
What two systems do you use when training for anaerobic power and what are their features?
ATP-PCr system: Short (5-10 seconds), high-intensity work intervals with 30-60 second rest intervals | Glycolytic system: Short (20-60 seconds), high-intensity work intervals
What are the three types of strength training exercises?
Increased muscle fiber number (only in extreme cases)
What must be done to see increases in strength?
Exercise near peak tension
How many days per week should you exercise to see improvements in strength?
How many days per week should you exercise to see maintenance of strength?
When strength and endurance training are combined, what happens?
Lower gains in strength
What is strength related to?
Cross sectional area of the muscle
Is there a gender difference in response to strength training?
Between untrained males or untrained females, who has greater absolute strength?
When does delayed onset muscle soreness appear (DOMS)?
24-48 hours after exercise
What is delayed onset muscle soreness appear (DOMS) due to?
Tiny tears in muscle fibers resulting in inflammatory response
What is static stretching?
Continuously holding a stretched position
What is dynamic stretching?
Ballistic stretching movements
What are some common training mistakes? (5)
Overtraining and undertraining | Nonspecific exercise | Failure to schedule long term training plan | Failure to taper before performance
What is tapering?
Short term reduction in training load prior to competition
What does tapering allow the muscles to do? (3)
Resynthesizes glycogen | Allows healing from training | Improves performance in both strength and endurance events
What is an erogenic aid?
A substance, appliance, or procedure that improves performance
What is a placebo?
A look-alike substance containing nothing that will improve performance
What is a double-blind study?
A study in which neither the investigators, nor the subjects are aware of who is receiving the treatment
Do nutritional supplements improve performance?
There is conflicting evidence that nutritional supplements improve performance
What are three types of nutritional supplements?
Protein | Creatine | Carnitine
Describe the effect of additional oxygen on performance. (Before/After/During)
Before or after exercise: no effect on performance | During exercise: may improve performance
Define blood doping and describe its potential for improving endurance performance.
Blood doping: Infusion of RBCs in effort to increase hemoglobin concentration and oxygen carrying capacity of blood | Effective in improving VO2 max and endurance performance
Explain the mechanism by which ingested buffers might improve anaerobic performances and just how they might be improved. (2)
Blood buffers (sodium bicarbonate): Improves performances of 1-10 minutes duration or repeated bouts of high-intensity exercise | No benefit for tasks of less than one minute
Explain how amphetamines might improve exercise performance. (3)
Catecholamine-like effect (cardiovascular/metabolic) | Improve performance in fatigued subjects only | No improvement in alert, non-fatigued subjects
Describe the various mechanisms by which caffeine might improve performance. (2)
May improve performance at muscle, nervous system, or the delivery of fuel to the muscle | Can elevate blood glucose and increase fat utilization (effect is variable and dose-related and may be diminished in regular users)
Identify the risks associated with using chewing tobacco to obtain a "high" from nicotine.
Nicotine: Can stimulate both sympathetic and parasympathetic nervous systems | Cardiovascular and gastrointestinal effects | Known to cause diseases of the mouth, including oral cancer
Describe the physiological and psychological effects of different types of warm-ups.
Physical Warm-Up: Causes both physiological and psychological changes that are beneficial to performance (Increased muscle temperature, arousal, focus on event)