Chapter 13/14/20: The Physiology of Training Flashcards
describe the principle of overload
increased capacity of a system in response to training above the level to which it is accustomed
what factors can contribute to overload?
intensity, duration and frequency
what does too much overload lead to? common issue in which group?
overtraining or overreaching, which is a common issue with elite athletes
describe the principle of reversibility
when training is stopped, the training effect is quickly lost
describe the principle of specificity
training effect is specific to:
1) muscle fibers recruited during exercise
2) type of contraction (eccentric, concentric, isometric)
3) energy system involved (aerobic vs. anaerobic)
how does the VO2 max for an athlete during their sport specific activity compare to their VO2 max on a treadmill?
VO2 max during sport specific activity were as high or higher than their VO2 max on a treadmill
is there a difference between men and women’s responses to training programs?
no, exercise prescriptions should be individualized
how does initial fitness level effect training improvement?
training improvement is always greater in individuals with lower initial fitness levels
how do genetics influence an individual’s response to training? evidence?
genetics play an important role, evidence with identical twin study: ten sets of identical twins went through the same training program- there was a similarity in the response of each pair, but improvement in VO2 max varied from 0-40%
how does training affect the VO2 max of high responders (genetically)?
high responders possess a relatively high untrained VO2 max which increases significantly with training
how does training effect the VO2 max of low responders (genetically)?
low responders possess a relatively low untrained VO2 max which does not increase significantly with training
how do genetics effect anaerobic training?
anaerobic training is more genetically determined, training can only improve anaerobic performance to a small degree
why is anaerobic capacity more genetically determined than aerobic capacity?
anaerobic capacity is largely dependent on fast (type IIx) fibers which are determined early in development
how does muscle fiber type change with aerobic training?
reduction in cross-sectional area of fast fibers and increase in cross-sectional area of slow fibers
how does capillary density change with aerobic training? consequence?
increased number of capillaries surrounding muscle fibers which enhances oxygen diffusion and improves removal of wastes
how does myoglobin content change during aerobic training? consequence?
increases muscle myoglobin content by 75-80% which supports the muscle’s increased capacity for oxidative metabolism after training
how does muscle mitochondria content change with aerobic training?
doubles within 5 weeks of training, then plateaus
what types of mitochondria are increased with endurance training?
both subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria
what does increasing volume of mitochondria in muscle fibers result in?
improved oxidative phosphorylation capacity and ability to utilize fat as fuel
how does aerobic training affect mitochondrial turnover?
training increases the breakdown of damaged mitochondria and replacement with healthy mitochondria (increases turnover)
term for breakdown of damaged mitochondrial
mitophagy
how does increased mitochondrial volume affect ADP levels? what does this result in?
increased mitochondrial volume decreases cytosolic [ADP] due to increased ADP transporters in mitochondrial membrane, which results in less lactate and H+ formation and less PC depletion
how does endurance training affect the O2 deficit at the onset of work? how?
endurance training reduces the O2 deficit at the onset of work; because more mitochondria can increase oxidative capacity
does aerobic training affect the absolute amount of oxygen consumed at a given work rate once steady state is reached?
no, does not change amount of oxygen consumed at a given workload once steady state is reached (still costs the same amount of oxygen)
how does low muscle glycogen influence endurance training-induced adaptations?
low muscle glycogen induces higher activation of PGC-1alpha (signaling molecule) which leads to increased protein synthesis and mitochondria formation
2 approaches to create low muscle glycogen, what may be a disadvantage to each?
1) restrict dietary carbs: may cause fatigue and limit training
2) train twice per day (every other day): second training session with lower muscle glycogen (lower performance)
effect of exercise duration on muscle fuel source
increased exercise duration increases fat utilization and decreases carb utilization
how do endurance trained athletes compare to untrained individuals with regards to fuel source?
endurance trained athletes use more fat and less carb than less-fit athletes during prolonged exercise at the same intensity
2 methods by which endurance training affect free-fatty acid and glucose utilization?
1) increased mitochondrial number —> increased beta oxidation enzymes
2) increased capillary density —> slows blood flow in muscle and increased FFA transporters —> increased uptake and utilization of FFA —> spares plasma glucose
how does increased mitochondrial volume with endurance training improve acid-based balance during exercise? (2 ways)
1) increased mitochondrial number —> increased FFA oxidation and decreased PFK activity —> decreased pyruvate —> decreased lactate and H+ formation —> blood pH maintained
2) increased mitochondrial number —> increased mitochondrial uptake of pyruvate and NADH —> decreased lactate and H+ formation —> blood pH maintained
how does endurance training affect the lactate threshold?
with endurance training, the lactate threshold occurs at a higher percentage of one’s VO2 max
which is more important in improving VO2 max: intensity or duration?
intensity