Principles of Exercise Training Flashcards
Overview of Programming
Successful exercise programs follow a comprehensive, systematic, and integrated approach to achieve optimal results
Consider the effect of an exercise on the entire kinetic chain
Rethink training program in terms of movement rather than exercise
Common goal of achieving, maintaining, or promoting desired levels of stability and mobility needed in the body
> stability
> mobility
The relationship between stability and mobility serves as a foundation to all programs
Stability: Ability to control the position or movement of a joint
Mobility: Degree of unrestricted or functional movement needed at a joint
Many programs fail to address functionality through:
integration
multijoint movements
multiplanar training
proprioceptively enriched environments
Integration:
Training all parameters of physical fitness to improve functional strength and neuromuscular efficiency
Multijoint movements:
Incorporate the entire kinetic chain vs. isolating single joints
Multiplanar training:
Creates movements in all three planes to reflect the movements of our ADLs
Proprioceptively enriched environments:
Unstable yet controllable environments in which exercises are performed in a manner that requires the body to use balance and stabilization mechanisms
General Training Principles
volume
intensity
overload
specificity
progression
Volume =
Cardiorespiratory: Frequency and duration of exercise bout
Resistance: Sets x reps
> Time under tension: Amount of time spent completing a full repetition
Intensity =
Cardiorespiratory: Level of work performed reflected through speed, grade, or Watts
Resistance: Amount of weight lifted
Overload =
To enhance physiological improvements and stimulate adaptations to training there must be a continual increase in demand placed on the system being trained
Can be applied to volume and intensity
Specificity =
Specific training adaptation or outcome is determined by the method of training
Also known as specific adaptations to imposed demands (SAID)
Progression =
Systematic application of overload to promote long-term benefits or prepare an athlete for a specific event
Implies the manipulation of training variables to elicit greater intensities or volumes of training
Increased demands on physiological systems must be applied gradually and systematically over time to allow for appropriate recovery and adaptation and to avoid overtraining and potential injury
Response to strength training
Muscle hypertrophy
Neural adaptations
Muscle hypertrophy =
Increased protein synthesis in muscle fiber—increased in physiologic CSA of the entire muscle
Primarily due to increase in fiber size, limited evidence implying increase in number of muscle fibers (hyperplasia)
Occurs in all muscle fibers but primarily in fast twitch
Neural adaptations =
Evident within the early phases of training:
> Increased area activated in cortex during motor task via fMRI
> Increased supraspinal motor drive
> Increased motor neuron excitability and discharge frequency of motor units
> Decreased neural inhibition
Imagery training shows documented strength gains
Increased strength seen in non-exercised muscle
Diminishing Returns =
Rate of fitness improvement diminishes over time as an individual approaches genetic potential
Not to be confused with a plateau effect
Reversibility =
Detraining: Partial or complete loss of any training-induced adaptation that occurs due to a decrease in training stimulus
May result in muscle atrophy evident by decreased muscle fiber CSA
Various aspects of fitness will demonstrate losses at different rates
Can occur quickly!
> 3-6% loss in first week
> After 10 days of immobilization, healthy individuals can experience up to 40% decrease in 1RM
Shift to maintenance training once goals are attained to prevent unwanted loss
Disuse =
Reduced protein synthesis in all muscle fiber types within a chronically immobilized limb
> Most notably with slow twitch
Slow twitch fibers are frequently used with ADLs and are subjected to greater relative disuse with immobilization vs. fast twitch fibers
Effects of immobilization:
Loss of strength is greatest when muscle is maintained in shortened position
Antigravity single-joint muscles show more rapid atrophy than other muscles
> Soleus, VMO, multifidus
Stress:
Nonspecific body response to any stimulus that overcomes, or threatens to overcome, the body’s ability to maintain homeostasis
General Adaptation Syndrome
Includes exercise-induced stress
Stress stimulates release of key hormones by ANS -> hypothalamus releases CRH -> stimulates pituitary gland to release ACTH -> release of cortisol from adrenal glands
Stress response is critical to survival but can have unhealthy consequences if sustained for prolonged periods
Theory of general adaptation—Hans Selye
Body responds to an external source of stress with a predictable biological pattern to maintain and restore internal homeostasis
Seyle theorized that this pattern of change occurs in reaction to any kind of stress leading to eventual disease conditions (e.g. ulcers, arthritis, HTN, arteriosclerosis, diabetes)
This pattern was termed general adaptation syndrome
Model explains the physiological manner that a body responds to stress by moving through specific stages
Theory of general adaptation—Hans Selye
stages:
Alarm or Shock Stage
Resistance or Adaptation Stage
Exhaustion Stage
Alarm or Shock Stage =
Initial fight-or-flight response
Decrease in effectiveness of the immune system making them more susceptible to injury or illness
Feeling fatigued, weak, sore during early phase of exercise program
May last a few days to several weeks
Resistance or Adaptation Stage =
Mobilization of internal resources in effort to return to homeostasis
Begins to restore balance through period of adaptation by altering its physiological structures
> Increased muscle CSA, improved motor unit synchronization
Characterized by the return of muscle’s normal function after losses experienced during alarm phase
May cause problems when body is not given adequate levels of recovery
Exhaustion Stage =
Prolonged exposure to stress without recovery depletes the body’s resources and tolerance of stressors
Immune system gradually declines and body’s ability to resist illness or injury is compromised
Adversely effects physiological systems contributing to disease as the body fails to maintain normal function
Commonly associated with excessive training and burnout, also known as overtraining
Overtraining
Attributed to inadequate recovery that compromises the body’s immune function and its ability to continue adapting
Characterized by the following signs and symptoms:
> Decreased performance over 1-2 weeks
> Increased RHR and/or BP
> Decreased body weight
> Nausea
> Disturbed sleep patterns and inability to attain restful sleep
> Muscle soreness and fatigue
> General irritability and altered moods
Periodization
Manageable training periods or planned cycles:
Microcycle: Days to weeks
Mesocycle: Weeks to months
Macrocycle: Months to years
Involves modifying program variables over time to effectively transition a program from a generalized approach toward one meeting specific needs and demands of activity
Additional programming considerations:
Order of sequence exercises are performed can impact both performance and injury
Power and heavy-strength exercises should be performed at the beginning of a workout
Perform primary or linear exercises before assistance or rotary exercises
Fatigue
Describes a decrease in performance experienced during sustained effort
Represents a system’s inability to maintain the desired or required work intensity
Sensation of being “tired”
Multifactorial and attributed to many causes:
> Peripheral factors (within muscles)
> Central factors (within the nervous system)
> Other factors (cardiopulmonary system, thermoregulatory system, tolerance for discomfort, mental toughness)
Energy systems - Fatigue:
Energy depletion: Inability to sustain energy supply that meets current exercising demands
As PCr is depleted, the system’s ability to regenerate ATP diminishes which reduces the body’s ability to sustain short duration, high-intensity exercise
Glycogen depletion depends on primarily the type of exercise, and muscle fiber type and exercise duration to a lesser degree
Glycogen levels can deplete more rapidly during higher intensity, sustained bouts of exercise than when they are utilized aerobically through Krebs cycle
Depletion from either type I or type II fibers depend on exercise intensity
During low intensity, endurance exercise, type I fibers will deplete glycogen faster than type II fibers which may not be recruited
As intensity of endurance activity increases, glycogen utilization from type IIa and ultimately type IIx fibers will increase
Certain muscles may fatigue faster than others
Metabolic byproducts
Accumulation of hydrogen ions in muscle results in tissue acidosis (decreased tissue pH)
Lower tissue pH impacts various events within the metabolic pathways that ultimately trigger fatigue due to the muscle’s inability to produce energy:
Decreased glycolytic-enzyme activity
Reduction in myosin-ATPase activity
Increased pain receptor sensitivity in muscle tissue
Decreased ability to release and reabsorb calcium from sarcoplasmic reticulum
Interference with calcium’s ability to bind to troponin
Neural fatigue
Acetylcholine (Ach): Neurotransmitter involved in voluntary muscle action
Acetylcholine (Ach):
Ach released from motor nerve -> binds to receptors on motor endplate -> opens ion channels allowing sodium to enter muscle fiber -> depolarization conducted down transverse tubule
After its release from the presynaptic membrane, it is quickly broken down to acetic acid and choline by acetylcholinesterase
Enzyme becomes hyperactive preventing Ach from binding to the postsynaptic membrane and inhibiting muscle activation
Or enzyme may become hypoactive allowing Ach to accumulate on the postsynaptic receptors and inhibiting muscle relaxation
Thermoregulatory stress:
Exercise in heat or any form of exercise that elevates core temperature requires the expenditure of additional energy to cool the body
Increases in core temperature shift the oxygen-dissociation curve downward to release more oxygen to fuel the additional work
Also increases utilization of carbohydrates that may accelerate glycogen depletion and fatigue
Cardiopulmonary fatigue
Passive respiration
Active respiration
When sweat loss becomes significant a decrease in blood volume affects blood flow and nutrient/oxygen delivery to various tissue
HR may increase to offset reductions in SV to maintain circulation which also requires additional oxygen
Inability to sustain cardiopulmonary efficiency decreases nutrients/oxygen delivery to and metabolic byproducts removal from tissue
Passive respiration—
muscles of respiration consume ~2% of total oxygen uptake
Active respiration—
may increase to 11% when additional muscles become involved during exercise and compromise the amount of available oxygen for exercising muscles
Mental toughness and tolerance for discomfort
Use of intrinsic and extrinsic motivators provides adequate distraction to enable an individual to last longer
Although not fully understood, motivators may negate an individual’s conscious or subconscious sensations of fatigue or desire to stop and allow them to tolerate greater levels of discomfort
Muscle Soreness
Overload and muscle damage (especially from eccentric training) provide a strong stimulus for growth but also lead to muscle soreness
Acute muscle soreness experienced during intense exercise, latter stages of exercise, and immediate recovery period
Generally the result of an accumulation of waste products (e.g. hydrogen ions) or temporary fluid shift exerting pressure on pain receptors
Delayed-onset muscle soreness (DOMS):
Microtrauma or microtears within myofibrils causing disarrangement of sarcomeres from mechanical stress placed on the muscle during training
Normally experienced between 12-72 hours after exercise
Believed to trigger an immune response releasing histamines and prostaglandins into local area causing edema or fluid accumulation inside the muscle compartment
Some of the muscle’s physiological and functional capabilities are compromised during this phase (DOMS)
until adequate repair has occurred:
Reduction in muscle’s force-generating capacity
Impaired muscle glycogen synthesis starting 6-12 hrs after exercise which compromises the muscle’s potential to store energy reserves
Structural damage evident by the presences of specific enzymes and myoglobin in the blood following training
Impaired calcium homeostasis that interferes with troponin binding
DOMS is inevitable when starting or progressing an exercise program
Minimize magnitude by:
Reduce initial volume of time in eccentric training
Start at lower intensities and increase gradually
Control exercise volume
