Week Ten Flashcards
What is aerobic exercise?
- Any activity that you can sustain for more than just a few minutes (‘Cardio Exercise’)
- Often considered the most important component of physical fitness and best indicator of overall health
What is cardiorespiratory endurance?
The ability of the lungs, heart and blood vessels to deliver adequate amounts of oxygen to the cells to meet the demands of prolonged physical activity.
What are Endurance Sports?
- A subset of sports in which the goal is prolonged athletic output over an extended distance or for an extended period of time
- They are aerobic by nature
- In general, the athlete is required to cover a fixed distance in the shortest time possible
What is the average aerobic fitness of an adult and athlete?
- Average sedentary adult = 35 ml/kg/min
- Elite athletes can be as high as = 90 ml/kg/min
How do athletes get a high aerobic fitness?
- They may have good genes, but they also train hard!
- When they train their bodies adapt
Why do we need acute responses to aerobic exercise?
-To supply oxygen and nutrients to the working muscles at a faster rate and volume
What is the basic physiology of breathing?
Breathing
-Oxygen is taken up by the alveoli in the lungs.
Blood passes through capillaries of the alveoli
-Oxygen is picked up by haemoglobin and transported to the heart
Heart
-Pumps oxygenated blood through the circulatory system to all organs and tissues in the body
Cells
-Oxygen is used to convert food through aerobic metabolism into adenosine triphosphate (ATP)
Physical Exertion
-More ATP is needed to perform the activity
Muscles
-Lungs, heart & blood vessels have to deliver more oxygen to the muscles to supply the required energy
During exercise what happens to the demand on oxygen and why?
- Oxygen demand during exercise increases
- Why? Muscles require more oxygen and nutrients (compared to rest) to produce the energy required for sustaining exercise
What is oxygen uptake related to?
- Mass of exercising muscle
- Metabolic efficiency
- Exercise intensity
What is maximum oxygen uptake?
-Maximal oxygen uptake: The greatest amount of oxygen that can be used at the cellular level for the entire body
What is the equation for determining VO2max?
-Fick Equation o VO2 = CO (aO2 – vO2 ) -CO = Cardiac Output -aO2 = arterial blood oxygen content -vO2 = venous blood oxygen content
What is cardiac output?
-The amount of blood pumped out of the heart in litres per minute (L/min) SV
What is the equation for cardiac output?
CO = HR x SV
What happens to cardiac output during exercise and why?
-Increases during exercise
Why?
-As a function of increases in HR and SV during exercise
What is heart rate?
-The number of times the heart beats per minute (beats per minute; bpm)
What happens to heart rate during exercise and why?
-HR increases during exercise
Why?
-Decreased/withdrawal parasympathetic stimulation and increased sympathetic stimulation,
-For the purpose of increasing the supply oxygen at a faster rate
What system is heart rate under?
-Heart Rate is under autonomic nervous control
What is the natural rhythm of heart rate?
100 bpm
What is the percentage of blood distribution in the body?
Heart= 7% Pulmonary vessels= 9% Systemic capillaries= 7% Systemic arterics and arterioles= 13% Systemic veins and venules= 64%
During exercise what does the ANS do?
-ANS regulates volume and distribution
-Sympathetic stimulation causes:
o Vasoconstriction and vasodilation depending on the bodies needs
What is stroke volume and the equation?
- Amount of blood pumped out of the heart each beat (l/min)
- SV = End Diastolic Volume – End Systolic Volume
What happens to stroke volume during exercise and why?
-Increases at the onset of exercise Why? -End-diastolic volume is increased by: o Increased venoconstriction and o Increased activity of the muscular pump (muscles contracting causing the blood to move faster through the one-way valves of the veins) = increased venous return
What is blood pressure?
-Pressure blood exerts against the arterial walls
o Systolic blood pressure = the pressure exerted against the arterial walls as blood is forcefully ejected during ventricular contraction (during systole)
What happens to blood pressure during exercise and why?
-Increases with exercise
Why?
-Higher stroke volume
o Rest systolic BP = 110 -139 mmHg,
o Maximal aerobic exercise = 200 - 260 mmHg
-Diastolic blood pressure = the pressure exerted against the arterial walls when no blood is being forcefully ejected through the vessels (during diastole)
o Stays the same or decreases
What is aerobic exercise?
Greatest impact on both oxygen uptake and carbon dioxide production
During aerobic exercise what happens?
- Large amounts of oxygen diffuse from the capillaries into the tissues
- Increased levels of carbon dioxide move from the tissue to the blood and blood to the alveoli
- Increased depth of breathing (Tidal Volume; VT)
- Increased frequency of breathing (f)
- Increased minute ventilation (VE)
What is the purpose for the responses to aerobic exercise?
-To maintain appropriate alveolar/blood concentrations of these gases
Why do chronic adaptations occur?
-Continued stimuli causes adaptation
What are respiratory adaptations during exercise?
-Pulmonary system has a big reserve (“overbuilt”) which meets the demands of vigorous exercise thus no need to change
-No consistent or significant changes of lung volumes or capacities
o Sport specific
-Land based no changes compared to non-athletes and athletes
-Swimming has seen increases in TLC and VC compared to land based and non-athletes
=Why swimmers breathing against a resistance, restricted breathing patter and repetition
-Maximal Exercise
o VE is increased
-Due to increase in frequency and VT
-Maintain voluntary ventilation due to improved strength and endurance on respiratory muscles
-Submax Exercise
o VT increases, frequency decreases
o Ventilation lower as a result of submax not being a major stress
What are muscular adaptations in exercise?
-Increase in the aerobic capacity of the trained musculature
o Increased capillary density
o Increase mitochondrial density
-This adaptation allows the athlete to perform a given absolute intensity of exercise with greater ease after aerobic endurance training
What are bone and connective tissue adaptations?
-Tendons, ligaments, and cartilage grow and become stronger proportional to the intensity of the exercise stimulus
o Consider weight-bearing activities
What is maximal aerobic power in factors related to aerobic endurance performance?
- As duration increases contribution from the aerobic energy system increases
- High correlation between VO2max and performance in aerobic endurance events
What is lactate threshold?
The speed or percentage of VO2max which represents the highest functional workload whereby lactate isn’t being accumulated to intolerable limits
What lactate threshold is a indicator of and what does an elite athlete have?
-Potentially a better indicator of endurance performance than VO2max
-All elite athletes have high VO2max’s
o The one who can sustain the intensity at the highest % of their VO2max is the better competitor
-Therefore, aerobic endurance athletes should incorporate training at levels of elevated blood and muscle lactate to improve their lactate threshold
What is exercise economy?
- A measure of the energy cost of activity at a given exercise velocity
- An improvement in exercise economy can enhance maximal aerobic power (VO2max) and lactate threshold
What is exercise mode?
-The activity performed
o E.g. swimming, running, cycling
-Exercise mode should be specific to the activity performed by the athlete/individual
o The more specific the training mode is to the sport, the more specific the adaptation is = improved performance
What is training frequency dependent on?
- Intensity
- Duration
- Training status
- Specific Sport Season
What is required to maintain improvements and
-Fewer sessions required to maintain than gain improvements
-More than twice a week to see improvement - 3-5 days per week
o Balance between adaptation and not overtraining
-Importance of rest
What is training intensity?
-Adaptations in the body are specific to the intensity of the training session
-The recommendation to exercise at 70% HR max to improve aerobic capacity is a general guideline
o Achieves sufficient intensity to stimulate training effect yet does not produce discomfort (e.g.. lactate accumulation) that prevents talking during the workout
o The lower limit may depend on an individual’s initial exercise capacity and state of training
-A previously sedentary person does not need to exercise above this threshold heart rate to improve physiological capacity
o Generally longer exercise duration offsets lower exercise intensity in terms of benefits
-20- 30 mins of exercise at 70% HR max and 45 mins of exercise at 60% HR max are both beneficial
When does aerobic capacity improve?
-Aerobic capacity improves if exercise intensity regularly maintains a HR between 55 and 75% of maximum
What is the age predicted HR equation?
208 – (0.7 x age)
What is HR reserved equation?
APMHR – resting heart rate (RHR)
What is target heart rate equation?
(HRR × exercise intensity) + RHR
What is ratings of perceived exertion?
- Can be used to regulate intensity of aerobic endurance training across changes in fitness level
- May be influenced by external environmental factors
What is power measurement?
- Cyclists may use power-measuring cranks and hubs to regulate exercise intensity
- % of max power output
- % of max power output which correlates to VO2 max
What is exercise duration?
-No threshold duration per workout exists for optimal aerobic improvement
What is exercise duration dependent on?
- Total work accomplished (duration or training volume)
- Exercise intensity
- The longer the exercise duration, the lower the exercise intensity
- Frequency
- Initial Fitness Level
What is exercise progression?
-Progression of an aerobic endurance program involves increasing the frequency, intensity, and duration
o Should not increase by more than 10% each week
What happens when exercise progression is now feasible?
- When it is not feasible to increase frequency or duration, progression can occur with intensity manipulation
- Progression of intensity should be monitored to prevent overtraining
