Components of physical function (chap 7) Flashcards
Physical activity
Any bodily movement produced by the contraction of skeletal mm that result in a substantial increase over resting energy expenditure
Exercise
Any planned and structured physical activity designed to improve or maintain physical fitness
Fitness
The ability to perform physical work
- requires cardiorespiratory functioning, mm strength and endurance, and musculoskeletal flexibility
- often measured by body’s max O2 consumption
VO2 max
Measure of body’s capacity to use oxygen.
- mL of O2 / kg per min
- dependent on the transport of O2, the O2 binding capacity of blood, cardiac funciton, O2 extraction capabilities and muscular oxidative potential
Aerobic exercise training
Cardiorespiratory endurance
- augmentation of the energy utilization of the mm by means of an exercise program
- improvement directly related to increased levels of oxidative enzymes in the mm, increased mitochondrial density and size, and an increased mm fiber capillary supply
Training for cardiorespiratory endurance
- dependent on exercise of sufficient frequency, intensity, and time
- training produces cardiovascular and/or muscular adaptation and is reflected in an individual’s endurance
- training must be specific to goal!
Adaptation
Results in increased efficiency of the cardiovascular system and the active mm
- represents variety of neurological, physical, and biochemical changes in the cardiovascular and muscular systems
- performance improves in that the same amount of work can be done after training but at a lower physiological cost (higher the initial level of fitness, greater the intensity of exercise needed to elicit a significant change)
Heart rate
60-100 bpm, regulated heavily by the autonomic NS
- influenced by age, gender, emotional state, level of conditioning, disease processes
- need to note quality (bounding, strong, regular, thready)
- should be normal within 5 minutes of rest
SV
Volume of blood pumped out of the ventricles with each beat
- correlated with strength of ventricular contraction
- 60% blood within heart is pumped out in healthy individual
CO
CO = HR x SV
- amount of blood pumped out by the ventricles each minute (5L in healthy adult)
- influenced by ventricular contractility
PR
Peripheral resistance
- opposition to flow
- decreases the closer towards the heart you move due to the size of the vessels
- measure of the amount of friction the blood encounters as it passes through the vessels
- necessary to keep the pressure gradient and keep blood moving
- dependent on viscosity (affected by H2O and glucose, NOT blood thinners which change clotting factor), blood vessel length, blood vessel diameter
BP
BP = CO x PR
- the fore per unit area exerted on the wall of a blood vessel by its contained blood (mmHg)
- normal = 120/80, HTN = >140/90
- during exercise, SBP will increase and DBP should not change or slightly decrease
SBP
Systolic blood pressure
- ventricular contraction = increased / highest pressure
DBP
Diastolic blood pressure
- ventricular filling = lowest pressure
Influential factors on BP
- Valsalva: remember to breathe!
- Inversión: ??
- Change in position
Respiratory rate
Number of breaths / min
- healthy adult 10-20 / min (regulated by ANS)
- influences: age, body size, stature/posture, exercise, fitness, position
- determine whether pt is breathing from diaphragm vs upper chest
O2 saturation
Helps determine a pt’s cardiopulmonary status by providing a digital read out of oxyhemoglobin saturation (pulse ox)
- normal O2: 95-98%
- level usually drops with chronic pulmonary conditions, but shouldn’t change with exercise if body is efficient
ATP production
ATP rebased during glucose breakdown and converted into energy that can immediately be used by the body (cells)
- Aerobic: 36 ATP (with water and CO2) = long lasting energy
- anaerobic: 2 ATP (with lactic acid): maybe 1-2 min of energy
- with conditioning, become more effective at burning energy and utilizing ATP
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Aerobic fitness depends on
- Cardiovascular system (vasoconstriction/dilation to meet metabolic needs and maintain BP)
- Respiratory system (how much O2 required for activity vs ability to utilize O2 by the body)
- Exercising muscles (vasodilation of exercising mm and mm fiber types)
Direct VO2 max measure
Analyze inspired air vs expired air during maximal cardiovascular exercise
- accurate but expensive
- used for diagnostic purposes/research
- usually uses bike or treadmill
Indirect VO2 max measure
Analyze inspired air vs expired air during submaximal cardiovascular exercise
- uses relationship between HR (CO) and VO2
- uses treadmill or bike
Predicted VO2 max
Data from standardized tests / metabolic formulas; no gases analyzed
- good for a large group of untrained individuals
- usually submaximal exercise
- bike, treadmill, etc
- other standard tests include 1.5 mile or 3 min step test
Normal physiological response to exercise
- Sympathetic nervous system response
- Cardiac effects
- Peripheral effects
Sympathetic nervous system response
Increase in blood flow to skeletal muscle via vasodilation and increase in O2 extraction
- decreased visceral blood flow (SNS?)
Factors affecting O2 consumption
- vascularity of the mm
- fiber distribution
- number of mitochondria
- oxidative mitochondrial enzymes present in the fibers
Cardiac effects
- Decrease in diastolic filling time
- No significant change in diastolic pressure
- Increase in
- myocardial contractility
- SV and CO and HR
- max O2 consumption
- SBP in proportion to O2 consumption and CO - HR (CO) and O2 consumption have a linear relationship
- Increased CO initially due to increased SV (increased venous return at <40-50% of aerobic capacity
- > 40-50% aerobic capacity, increased CO due to increased HR
- MHR may be achieved before max O2 consumption
Peripheral effects
Overall decrease in total peripheral resistance (TPR) with activity
- vasodilation to working mm
- vasoconstriction of vessels from non-working mm and organ systems
- increased CO
- increased SBP
Benies of cardiovascular exercise
- reduced resting HR and reduced HR at a standard exercise load
- increased efficiency of the heart
- decreased resting BP
- can improve VO2 max 5-30% and up to 50% in endurance athletes
- increase utilization of fats and carbs
- increased production and size of mitochondria = increased efficiency / energy usage = increased energy
Developing a conditioning program
- Mode of exercise
- Frequency of exercise
- Duration of exercise
- Intensity of exercise
Mode of exercise
Exercises that involve repetitive, larg-mm movements that are rhythmical in nature and use large amounts of O2
- running, walking, swimming, cycling
- benefits are optimized when programs are planned to meet the individual needs and capacities of the participants
Frequency of exercise
Usually 3-5x / week *based on experience levels, intensity, and goals
- novice (<6 mo): 2-3x / week
- intermediate (6-12 mo): 3-4x / week
- experienced (>1 y): 4-5+x / week
- significant deconditioning may need increased times per day for short duration
Duration of exercise
Generally 20-30 min of continuos, intermittent, or circuit training aerobic activity
- depends on intensity
- reconditioned pt cant have high intensity or duration
Variations of aerobic exercise
- min of 10 min bouts multiple times per day necessary to improve aerobic capacity (cumulative)
- however, 3-5 min bouts in a de conditioned pt IS effective, increasing to longer sessions as able — consistency is preferred
Continuous training
No rest interval, exercise is performed for entire duration and changes minimally
- same resistance at same speed
- submaximal energy requirement must be sustained
- aerobic, stress on slow twitch fibers
- 20-60 min
- work rate is increased progressively as training improvements are achieved
- overload can be accomplished by increasing exercise duration
Interval training
Repeated higher intensity bouts (80%) with active rest (30-45%)
- 1:1 or 1:1.5 high/low intensity ratio
- relief interval can be passive (rest) or active (work- less intense). ATP and O2 are replenished and increase in VO2 max occurs
- longer the work interval, Moore aerobic system is stressed
- total amount of work completed is greater than that of continuous training
Circuit training
Employs several modes of that mix large and small mm groups as well as static and dynamic effort
- improves strength and endurance by stressing both anaerobic and aerobic systems
- can involve large and small mm groups and a mix of static and dynamic effort
Overload principle
Overload is stress on organism that is greater than that regularly encountered during everyday life
- to improve cardiovascular and muscular endurance, overload must be applied
- exercise load must be above the training stimulus threshold for adaptation to occur
- conditioning response generally occurs at 60-90% MHR and 50-85% VO2 max
Intensity of CV exercise
Should be between 60-90% of MHR
- intensity plays the principle role in maintaining increases in aerobic power
- pt MUST train at least at 60% of MHR for minimal improvement in CV endurance
- 70% considered moderate
- up to 90% for highly trained individuals
Calculating MHR
MHR = 220 - age
Target HR
MHR x 0.6 and MHR x 0.9 = range
Karvonen equation (target HR)
Resting HR + [% intensity (MHR - resting HR)]
Warm up and cool down
- should be GRADUAL and be done both at the start and completion of any aerobic exercise training
- lower intensity, but sufficient to increase core and mm temp without fatigue (less than 60% MHR)
- should last 5-15 min
- can include calisthenics, slow walking, and stretching
- exercise STARTS once HR in range
- deconditioned pts need more time for safe adaptation
Deconditioning
Reduction in work capacity can be lost in as little as 12 days
- one loses 7% aerobic capacity per week on bed rest
CV endurance training principle to keep in mind
- overload principle: to improve, overload must be applied
- specificity principle: specificity ot training to goal
- reversibility principle: benefits of exercise are transient and reversible
- FITT equation: frequency, intensity, time, and type
