The body's response to aerobic exercise Flashcards
what is physical exercise
is defined as a bodily movement that is produced by contraction of skeletal muscle, sustainability increasing energy expenditure
what is physical fitness
is a set of attributes that people possess or achieve that relates to the ability to perform physical activity
what are the health related components of fitness
cardiovascular endurance, muscle strength/ endurance, flexibility, body composition
what does exercise do
planned, structured, repetitive, done to improve or maintain one or more components of physical fitness
what is aerobic exercise designed to do
aerobic exercise id designed to increase cardiovascular fitness. sustained exercise that uses the aerobic pathways energy supply and training adaptations result in more efficient aerobic energy pathways
energy for exercises
ATP splitting- ATP+H20=ADP+PO, CP splitting- CP+ADP=C+ATP, anaerobic glycolysis- G/G+Pi+ADP=H+ + lactate +ATP
what is aerobic metabolism
carbohydrates/ free fatty acids/ protein+O2+PI+ADP+H20+CO2+ATP
oxygen and exercise
O2 is essential for aerobic exercise. time lag present in aerobic exercise. VO2 is the volume of oxygen consumed per Kg/min.
recovery oxygen consumption (EPOC)
replenishment of energy stores, systemic requirements, restore oxygen levels in blood, repair muscle, restore body back to normal temp and metabolic rate
oxygen consumption- VO2
at rest the oxygen consumption per Kg of body weight is relatively constant for everyone in the absence of injury or disease,
VO2 at rest- 300ml/min, VO2 with activity- 1000ml/min (walking briskly), VO2 with exercise (3000ml/min)- run at 12km/hour (mod), VO2 with exercise= 6000ml/min (elite)
what are functional activities calculated as
METS (metabolic equivalent of task)
what is VO2 max
is when increase workload can only occur through anaerobic glycolysis, thus VO2 max is the measure of an individuals aerobic capacity for activity, differences in aerobic capacity effect exercise tolerance
respiratory system response to exercise
potential increase from 6L/min to 200L/min, increase in: respiratory rate, TV, rate/depth breathing, faster delivery of fresh air into lungs, improved diffusion, as we stretch alveoli with big breaths- the ability for oxygen to go in increases- bigger SA for diffusion, the membrane becomes less thick
effect of ventilation on exercise
in a normal person, ventilation shouldn’t impede ability to do exercise- when working at 80% VO2 max we only use 50-60% MBC
cardiovascular system response to exercise
cardio output (CO+SV*HR) rises with exercise in proportion with VO2 max (usually 5l/min), cardiac reserve is the ration between the maximum CO a person can achieve and that at rest, average can increase CO by 4-5X, elite athlete- 6-8X, person with heart disease- 0
blood flow during oxygen
pulmonary perfusions increase up to 5X that at rest, increased blood supply to skeletal muscle (up to 10 folds) and skin (up to 5 fold), half the supply to digestion and kidneys
blood pressure and equation
CO*PR, normal blood pressure 120/80 systolic pressure, with the vessels during ventricular contraction. diastolic is the pressure within the vessel when the heart isn’t contracting
blood pressure during exercise
so when you exercise your heart beats stronger and faster therefore systolic HR increases significantly with exercise to max values of 200. however, diastolic pressure shouldn’t change and if anything will decrease slightly due to vasodilation which in turn will reduce PR
blood pressure during exercise- baroreceptors
will detect the increase in systolic pressure and via increased parasympathetic activity of the body will vasodilator vessels
blood pressure during exercise- specific exercise
UL this results in higher systolic and diastolic BP compared to legs. due to less decrease in PR due to muscle masses involved- BV larger in LL. in static work and WT lifting PR doesn’t decrease therefore BP increases proportional to exercise intensity particularly during exertion phase of WT lifting- static exercise is harder on heart dynamic. BP can increase by 50% in elite athletes
blood pressure during exercise- terminology
MAP- mean arterial pressure, TPR- total peripheral resistance, CO- cardiac output, systolic BP increases steady max, MAP rarely exceed 120mmHg- doesn’t change much due to drop in diastolic, MAP- CO*TPR
Effects of exercise
increase in fat breakdown through the usage in aerobic metabolism, increase in heart size due to its use during response to exercise, decrease BP, improve O2 uptake and utilisation due to increase number of mitochondria and increase capillary density, endorphin release- reduce fear, increase plasma volume, increase BF, improved muscles more efficient, improvements in ability with ADL’s. reduced impact on services due to healthy lifestyle
principles of cardiovascular exercise design- FITT principle
F- 3-5 times a week, intensity- overload principle and moderate, Time- aim 20-60 mins of continuous or intermittent activity a day, type- rhythmical ,using large muscle groups, variety to avoid muscle fatigue
potential complications of immobility
respiratory- pneumonia and pulmonary embolism, cardiovascular- hypertension/ cardiac muscle atrophy/ FVT, metabolic- glucose intolerance and negative nitrogen balance, neurological- depression, MSK- osteoporosis/ muscle atrophy and weakness, gastrointestinal- constipation
the acutely unwell and the acute effects of exercise- problems
decreased ventilation and perfusion, decreased V/Q matching, fluid shifts, reconditioning, risk of complications, anxiety and depression, loss of function
the acutely unwell and the acute effects of exercise- benefits
increase/redistributes ventilation and perfusion, increased circulation, muscle activity, reduces risks, endorphins, functional independence
exercise limitations to downward spiral
fear of exercise, avoidance, reconditioning, inactivity, loss of confidence, social isolation
acute effects of exercise- what happens before/during/after exercise
energy requirements, need for oxygen, respiratory system response, CVS response (including BP and blood flow), diffusion at lungs and at tissue level, brain/psychology
assessment strategies
breathing pattern/ respiratory rate/ auscultation, blood tests/ pulse oximetry, heart rate/rhythm, blood pressure, exertion scale/ functional tests/ biopsychosocial approach to assessment, QOL questionnaire/ depression scores
what would we assess to ensure a patient is safe to exercise
stability, oxygen saturation, respiratory rate and pattern, HR/rhythm, BP, drugs, muscle contraction, joint range, CO-pathologies, psychological factors, sensory status, general conditions
O2 demand
exercise increases our demand for oxygen but so does illness, for every 0.6° rises in temp- O2 demand increases by 10%, critically ill patient with sepsis- 50-60% increase, multiple trauma- 100%
O2- demand- limitations
airflow resistance, diffusion limitations, tissue resistance, altered mechanics/ structures, fear avoidance
CV changes in ill patients
unable to CO increase, altered ability for a normal BP response, diffusion limitation at tissue level, decrease ability to increase BF, fear and avoidance, decondition
benefits of exercising patients with cardiac disease
increased Hb concentrations, increase mitochondria, muscle fibre type change from IIB, TO IIA, cardiac hypertrophy, angiogenesis , increase myoglobin