Training Changes during Submaximal Exercise

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Training Changes - during Submaximal Exercise

• 1. No change or slight decrease in oxygen
  consumption
• 2. Decrease in muscle glycogen usage
• 3. Decrease in lactic acid production
• 4. No change or slight decrease in cardiac output

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Training Changes - during Submaximal Exercise

• 5. Increase in stroke volume
• 6. Decrease in heart rate
• 7. Decrease in muscle blood flow

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Training Changes - during Maximal Exercise

• 1. Increase in maximal aerobic power
• 2. Increase in cardiac output
• 3. Increase in stroke volume
• 4. No change or slight decrease in HR
• 5. Increase in lactic acid production
• 6. No change in muscle blood flow

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Respiratory Changes

• Increased maximal minute ventilation
• Increased ventilatory efficiency
• Larger diffusion capacity

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Other Training Changes

• Body Composition
• Cholesterol and triglyceride levels
• Blood Pressure
• Connective Tissues

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Principles of Training

• Overload
• Specificity
• Individual Differences
• Reversibility

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Individual Differences Principle

• Relative fitness level at the start of training
• Genetic factors

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Reversibility Principle

• Detraining occurs rapidly
• 1 to 2 weeks of detraining
• Reductions in metabolic and working capacity can
  be measured
• Many of the training improvements are lost within
  several months

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Training Principles

• Determining the Predominant Energy System
• Determining intensity of training
• Determining frequency and duration of training
• Training phases
• Training Methods

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Determining Predominant Energy System

• Time of Performance
• Link maximal performance time to energy system
  concepts (Fox, 1993 Table 12.1)

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Determining Training Intensity

• Percentage of Maximal Heart Rate
• Karvonen Formula
• Minute Ventilation and the Anaerobic Threshold
• Blood Lactic Acid and the Anaerobic Threshold

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Intensity of Training

• Max HR 220 - age (yr)
• Max HR 200 - (0.5 x age (yr))
• HRR HR max - RHR

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Frequency and Duration

• Effect on the magnitude of the training results
• Trade off 1 day/wk for 30 min 3 days/wk for
  15 min provided same intensity

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Specificity of Training

• Physiological capacity
• Muscle Group
• Neuromuscular

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Other Principles of Training

• Mode of exercise
• Maintenance of training
• Detraining

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Interval-Training Variables

• Rate and distance of work interval
• Number of repetitions during each workout
• Relief interval or the time between work
  intervals
• Type of activity during relief interval
• Frequency of training per week

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Interval Training - Rate Distance of Work
Interval

• Long-duration work intervals at low intensities
• Medium duration intervals performed at moderate
  intensities
• Short work bouts at high intensity

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Interval Training Intensity

• Heart rate - 80-90 of HRR or 85-95 of HRmax
• Rule of thumb - rasise HR to 180 b/min
• Based on number of work intervals that can be
  performed in the workout
• Wilts method for running
• 1st step - run mile for time
• Determine average 440yd time
• Shorter distances 55-220 yd 1.5-5.0 sec slower
  than time for given distance from running start

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Training Effects-Biochemical

• Increased myoglobin content - specific to trained
  muscles - tied in to exercise frequency
• Improved oxidation of carbohydrate
• Improved oxidation of fat oxidation

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Biochemical - Anaerobic Changes with Training

• Increased capacity of the Phosphagen System
• Muscle stores of ATP, PC
• Increased activities of enzymes
• Increased glycolytic capacity

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Cardiorespiratory Changes at Rest

• Increased heart size (hypertrophy)
• Decreased heart rate (bradycardia)
• Increased stroke volume
• Increased blood volume and hemoglobin
• Increased capillary density and hypertrophy of
  skeletal muscle

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Characteristics of Hormones

• Chemical messenger produced and stored in
  glandular tissues
• Endocrine glands are ductless, hormones secreted
  into body fluids (blood, lymph)
• Hormones circulate affect a variety of target
  tissues
• Most hormones are generalized in their action
  circulate widely
• Local hormones (acetylcholine) released by
  parasympathetic and skeletal muscle nerve endings
  have local effects

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Chemical Classification

• Steroid
• Chemical structure similar to cholesterol
• Lipid soluble
• Nonsteroid

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Hormone Actions

• Specific hormone receptors possessed by the
  target tissue
• Polypeptide hormones interact with receptors on
  cell surface
• Lock (receptor) and key (hormone) arrangement
• Hormone-receptor complex

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Hormone Action

• Cells have 2,000 to 10,0000 receptors
• Nonsteroidal hormone receptors located on cell
  membrane
• Steroid hormone receptor found in cells
  cytoplasm or in nucleus

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Steroid Hormones

• Steroid hormone binds to specific receptor
• Hormone-receptor complex enters nucleus
• Binds to part of the cells DNA
• Activates certain gene

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Nonsteroid Hormones

• Nonsteroid hormone-receptor triggers formation of
  intracellular second messenger
• Cyclic adenosine monophosphate (cyclic AMP or
  cAMP)

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Control of Hormone Release

• Released in relatively brief bursts

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Number of Receptors

• Plasma levels not always best indicator of actual
  hormone activity

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Insulin Response to Exercise

• Moderate, prolonged exercise ---gt decrease blood
  glucose
• Compensated by glucose release from liver
  kidney
• Decline in insulin over time is due to
  catecholamine secretion which suppresses insulin
  secretion
• Epinephine directly effects stimulation of
  glycogenolysis
• Decline in blood insulin levels during exercise
  helps to minimize glucose uptake by nonactive
  muscle - sparing for brain and skeletal muscle

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Glucagon - Insulin Antagonist

• Alpha cells of pancreas secreted when blood
  glucose levels are low
• Two effects on hepatic metabolism
• enhance glycogenolysis
• increases gluconeogenesis
• Activates the adenylate cyclase cascade mechanism
• Glucagon also follows blood alanine levels
  released from catabolic effect of cortisol in
  muscle
• Glucagon promotes hepatic amino acid uptake and
  gluconeogenesis

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Autonomic Nervous System

• Parasympathetic n.s. controls resting functions.
  (slow HR, stim digestion)
• ACH promotes Cl- slows heart by lowering resting
  membrane potential
• Sympathetic n.s. controls flight-or-fight
  responses
• Norepinephrine promotes Na, Ca entry across
  cell membrane spees up heart by stimulating
  cation influx
• Sympathetic activity stimulates secretion from
  adrenal medulla of norepinephrine and epineprine
  (1 to 4 ratio)

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Posterior Pituitary and ADH Secretion

• Antidiuretic hormone (ADH) functions
  w/aldosterone to maintain fluid and electrolyte
  balance
• Osmolality (electrolyte concentration)and
  arterial pressure stimuli
• Severe sweating --gt concentrates the blood --gt
  hypothalmus stim posterior pituitary results in
  ADH secretion --gt leading to water retention
• Pressure receptors in left atrium vascular
  baroreceptors --gt dehydration--gtreduces blood
  pressure--gt hypothalmus stimulated --gt ADH
  secretion

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Exercise in the Heat and Cold

• Introduction
• Range of normal resting body temperature
• Core temperature
• Temperature Regulation

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Temperature Regulation

• Temperature is a measure of the kinetic activity
  of its molecules.
• Temperature of the body is directly proportional
  to the amount of heat stored
• Control rate of heat gain and heat loss
• Rate of heat gain rate of heat loss - Thermal
  Balance

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Heat Production

• Metabolism
• Shivering
• Nonshivering thermogenesis
• Metabolism of food

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Heat Loss

• Thermal gradients
• Radiation
• Conduction
• Convection
• Evaporation

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Conduction

• Definition transfer of heat from the body to an
  object (or vice versa) or heat transfer within
  the organism down a termal gradient

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Convection

• Definition Conduction of heat to or from air or
  water. Heat must first be conducted to the
  air/water and then carried away by the convection
  currents.
• 12 of heat loss at room temperature
• Greater in the wind

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Evaporation

• Latent heat of vaporization - quantity of heat
  absorbed by sweat as it evaporates
• 1 gram sweat changing from water to vapor is
  2422.3 J or 0.58 kcal
• At rest, comfortable environment, 25 of heat
  loss.

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Evaporation

• Insensible loss 600 ml/day or continual loss of
  12-18 kcal/hr
• Unacclimatized max sweat rate 1.5 l/hr
• Acclimatized max sweat rate 4 l/hr
• or 3.6 kg/hr weight loss

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Activation of Heat Loss Reflexes

• Cardiovascualar control center is inhibited
• Dilation of skin blood vessels
• Increase in blood flow to skin
• Conduct heat from core to periphery
• Increase in skin temperature
• radiation and convection from skin to Env.
• Stimulate sweat glands --gt evap heat loss

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Acclimatization to Heat

• 1 to 6 weeks and requires exercise training
• Requires elevated core temp and an hourly sweat
  rate of at least 4-600 ml at temps greater than
  30o C for at least 5 days.
• Is humidity specific
• Initial fitness level effects rate of
  acclimatization

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Cardiovascular Adaptations

• 3-27 increase in plasma volume
• Maintain SV, central blood volume, sweating
  capacity
• Plasma volume increase due to increase in plasma
  proteins ( 1 gram plasma protein/15 g of water
• Blood flow to skin decreases
• Helps to restore central blood volume

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Sweating Response

• Threefold increase in sweating capacity
• Decreased sodium loss due to increased
  aldosterone secretion
• Fall in sweating threshold early onset of
  sweating
• Reflects a lower setting of the hypothalamic
  set-point

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Integration of Psychological, Physiological, and
Biomechanical Characteristics
( Time / Rate / Balance (Stability))
Addiction (Overtrained) Commitment
(Rested) Involuntary need Voluntary need Less
Time Balanced Time Impaired Social,
Behavioral Stable Social, Behavioral Breakdown gt
Build-up Breakdown lt-gt Build-up Decreased
Efficiency Increased Efficiency Proteins
required for Energy Proteins Spared Tissue
Breakdown gt Remodel Tissue Breakdown lt
Remodel Failure --gt Injury Adaptation --gt
Efficiency Exercise controls the
trainer Trainer Controls the exercise
Psychological
Physiological
Biomechanical
Practical