What are three sources of ATP
- cell supply: small amount
- Phosphocreatine: short, intense exercise; sprinting and power lifting
- Carbohydrates and dats
Compare aerobic metabolism to anaerobic metabolism
Aerobic metabolism is most efficient: through glycolysis-citric acid pathways, but requires oxygen, used for long term endurance exercise
- anaerobic metabolism is faster, pyruvate to lactate, fatty acids not used, but less afficient than aerobic
What are the three types of hormones regulating metabolism during exercise
- Conversion of triglycerides to glycerol and fatty acids: cortisol, catecholamines, growth hormone
- Conversion of liver glycogen raises plasma glucose levels: glucagon, catecholamines, cortisol
- Insulin secretion suppressed during exercise: cells other than muscle fibers reduce glucose uptake, actively-contracting muscle cells do not require insulin for glucose uptake
What are three factors that limit exercise?
- Oxygen consumption is related to exercise intensity: is a measure of cellular respiration
- Excess postexercise oxygen consumption used to restore ATP, myoglobin levels of oxygen
- ability to deliver oxygen and nutrients to the muscle at a rate that supports aerobic metabolism
How does the ability of muscle fibers to obtain and use oxygen limit exercise?
- Mitochondria are limited in number
- insufficient oxygen supply
- not limiting for maximum exercise capacity
- influences submaximal exercise capacity
What are the three ventilatory responses to exercise
- increased rate and depth of breathing
- Exercise hyperventilation feedforward signals from the motor cortes and sensory feedback from peripheral receptors
- Carotid and aortic chemoreceptors
- Proprioreceptors in joints
- Mechanoreceptors in muscles
- Arterial Po2, Pco22 and pH do not change significantly during mild to moderate exercise
What are the three cardiovascular responses to exercise?
- Cardiac output rises dramatically due to faster heart rate and greater stroke volume
- Distribution of blood flow shifts toward muscle
- blood pressure rises slightly during exercise because of skeletal muscle dilation
What is the breakdown if the cardiac output equation?
CO = (SA node rate (dec. parasympathetic activity) + autonomic nervous system input (^ sympathetic activity) x (venous return + force of contraction (^ sympathetic activity)
How does the baroreceptor reflex adjust to exercise?
THEORIES:
- signals from motor cortex reset baroreceptor threshold
- afferent neurons are blocked by presynaptic inhibition
- muscle chemoreceptors (postulated) are sensitive to metabolites
How does the body regulate temperature homeostasis during exercise
- Sweating: evaporative cooling
- Increased cutaneous blood flow - convection
- Body adapts to repeated exercise in hot environments
What is the feedforward sequence response to exercise
proprioreceptors in muscle and joints -> motor cortex -> descending signals to
- Exercising muscles
- Cardiovascular control centre
- Respiratory control centre
- Limbic system
- sympathetic discharge casuing vasoconstriction, increasing blood pressure
What is the Rating of Perceived Exertion RPE
- conscious manifestation of the integration of signals from muscle, joints, central CV and respiratory functions, CNS and psychological
What are the three RPE equations?
- ^ RPE infinite to core body temperature
- ^ RPE 1/infinite arousal/fuel reserves
- “maximally tolerable” = physiological limits
What is the endspurt phenomenon?
Decreased uncertainty of your ability to complete something towards the end
