Chapter 13,14,20 Flashcards
What are the three principles of training
- overload
- reversibility
- specificity
explain overload in training
overload: need to stress body - adaptation
* increased capacity of a system in response to training above the level to which it is accustomed — intensity, duration, frequency
* too much leads to overtaining or overreaching
** if negative on the slope it is overload and positive slope is recovery – over time leads to improvement ** - slide 4
explain what reversibility is in training
when training is stopped – the training effect is quickly lost
- if you stop exercise or have overtraining fitness decreases
Overtraining is what
too much stress
* cant get to origional fitness
* downward trend
explain specificity in training
training effect is specific to:
* muscle fibers recruited during exercise
* type of contraction (eccentric, concentric, isometric)
* energy system involved (aerobic vs. anaerobic)
explain the influence of sex on training
men and women respond similarly to training programs
* exercise prescriptions should be individualized – strength or % improvement is similar
Explain the influence of initial fitness level
training improvement is always greater in individuals with lower initial fitness
- 50% increase in VO2 max in sedentary adults
- 10-20% improvement in normal, active subjects
- 3-5% improvement in trained athletes
Why are there no large improvements in trained individuals in fitness
- dont have unlimited capacity to grow blood volume
- only increase up to certain point
- similar to mitochondrial amount when you reach the “cap”
how does genetics play a role in how an individual responds to training
while there is a similar response in twins the improvement in VO2 max varied from 0-40%
What is the best way to determine the role of genetics in exercise
TWIN studies
Explain genotype E to how genetics influences VO2 max in training
- High responders (genotype e) == have ideal genetic makeup required for champion endurance athletes
– possess a realtively high untrained VO2max (80-90% w/o any endurance training)
Explain genotype A to how genetics influences VO2 max in training
- low responseres (genotype a) == possess a relatively low untrained VO2max
– often exhibit limited exercise training response (ie. McArdle’s disease = prevent exercise)
is anaerobic or aerobic capacity more geneticlally determined
anaerobic training is more genetically determined than aerobic capacity
- training can only improve anaerobic performance to a small degree
- dependent largely on fast (IIx fibers)
- determined early in development
What 4 labratory tests are used to quantify endurance exercise portal
- blood lactate
- expired ventilation (VT/LT)
- economy
- VO2 max
What adaptations occur in the muscle and how do they occur
stimulus repeated excitation and contraction of muscle fibers during endurance training stimulates changes in their structure and function
What 4 adaptations occur in the muscle during endurance training
- muscle fiber type
- capillary density
- myoglobin content
- mitochondrial function
explain the shift in muscle fiber types with exercise
fast-to-slow shift in muscle fiber type
* reduction in (cross sectional area of) fast fibers and increase in (cross sectional area of slow fibers) number of slow fibers
what is the magnitude of fiber type deterined by
- magnitude of fiber type change determined by duration, type of training and genetics
What is capillary density
blood vessel density surrounding muscle fibers
With an increased number of capillaries surrounding muscle fibers what 2 things improve
- enhanced diffusion of oxygen –> want blood moving as slowly as possible (high density) to diffuse more O2
- improved removal of wastes
What happens to the myoglobin conent with endurance training
endurance training increases muscle myogloin by 75-80% –> maximize oxidative metabolism
With more myoglobin content with endurance training what is its effect
supports muscle’s increased capacity for oxidative metabolism after training
what is the timeline for muscle mitochondria to adapt to training
muscle mitochondria adapts quickly to training
* doubles within 5 weeks of training
how is mitochondrial volume effected by exercise and what are the effects on both SS and IMF mitochondria
training increases volume of both subsarcolemmal and intermyofibrillar mitochondria in muscle fibers
Due to the volume increase in mitochondria with training what are the three physiological responses
- improved oxidative capacity and ability ot utilize fat as fuel
- intreases mitochondrial turnover ( breakdown of damaged mitochondria and replace with healthy mitochondria –> increase mitochondria work at the same time so they are able to preserve glycogen stroes and increase fat usage
- breakdown damaged mitochondria
what is mitophagy
breakdown of damaged mitochondria (recycle mitochondria)
What are the two places of significance of increased mitochondrial volume
- increase mitochondrial volume = greater capacity for oxidative phosphorylation
- increase mitochondrial volume and decreases cytosolic [ADP] due to more ADP transporters in mitochondrial membrane
what is the effect of an increase mitochondrial volume and decreases cytosolic [ADP] due to more ADP transporters in mitochondrial membrane
- less lactate and H+ formation
- less PC depletion
(instead of using the same areas within the mitochondria b/c mitochondria is larger it can pass through different areas giving the same energy
endurance training does what to the O2 deficit at the onset of work
with endurance training there is a faster rise in O2 uptake (less O2 deficit) which results in less lactate formation and less PC depletion –> reach steady state faster
If you are exercising at a constant work rate and you do the same work rate before and after training what happens to the O2 consumption
the O2 consumption doesnt change at that given rate
why is there very little impact on O2 consumption with endurance training
*
because the energy cost is still there but just how fast can generate energy from the oxidative sources is different
what two things contribute to exercise-induced adaptation to endurance training
primary and secondary signaling molecules
what molecule acts on all three adaptations: fast-to-slow fiber type shift, mitochondrial biogenesis, synthesis of antioxidant enxymes
PGC-1alpha
Low muscle glycogen is what type of influence on endurane training - induced adaptations
positive influence
* promotes increased protein synthesis and mitochondria formation due to higher activation of PGC-1apha
What are the two approaches to change CHO availability and endurance training adaptations
- restrict dietary carbohydrates = may cuase fatigue and limit training – not stress other places in body
- train twice per day (every other day) = second training session with lower muscle glycogen
what is the effect of endurance trained athletes on muscle fuel source
endurane trained athletes use more fat and less CHO than less trained during prolonged exercise and same intensity
How does endurance training effect capillaries
more endurance training –> increased capillary density –> slower blood flow in the muscle and increased FFA transporters –> increased uptake of FFA –> increase FFA utilization –>
- increased beta oxidation enzymes and carnitine transferase
- spare plasma glucose
endurance training promotes utilization of FFA during exercise – b/c upregulation of enzymes in FFA transport – transport FFA across cell membrane into muscle fiber
carnitine essential for transport FFA across mitochondria membrane – where beta oxidation occur – endurance training increases carnitine transferase – ensure efficient delivery of FFA to site of beta oxidation
How does endurance training effect mitochondria
more endurance training –> increased mitochondrial number –> increased beta oxidation enzymes and carnitine transferase
how does endurance exercise training improve acid-base balance
increase mitochondria –> increase FFA oxidation and decreased PFK activity –> decreased pyruvate formation - (increased H4 form of LDH)-> decreased lactate and H+ formation –> blood pH maintained
increase mitochondria –> increase mitochondrial uptake of pyruvate and NADH –> decreased lactate and H+ formation –> blood pH maintained
decreased need for glycolysis –> less H+ and pyruvate formed –> less change in blood pH
what does H4 form of LDH do
encourage lactate to pyruvate
- decrease lactate and maintain pH
What happens to the lactate threshold in trained individuals
trained == shift right and LT at higher VO2 max
What are the 7 cardiovascular adaptations to training
- maximal endurance capacity (VO2 max)
- cardiac output
- heart size
- heart rate (resting, submax, max, recovery)
- SV
- blood volume
- a-v O2 difference
can you imporve VO2 max with 12 mo. of endurance training
- to improve VO2 max you must exercise close to or b/t LT
explain the realationship between intensity and duration and frequence of exercise and VO2max and the risks
- As you increase VO2 max and incraese frequency and duration the risk of orthopedic problems and cardiac complications increases exponentially from 80-100 Vo2 max and 4-5 days of frequency
- as you increase VO2 max, frequency and duration there are large improvements in VO2 max but plateaus once you reach 80% of VO2 max
there is an optimal training intensity, frequency and duration that is between 60-80 VO2max, 3-4 days/wk, and 20-30 min/day
at what exercise intensity shows the greatest improvement in VO2 max
at about 80% VO2 max greatest improvement
- reduce frequency and duration to get best rance
What is the most important factor in improving VO2 max
training intensity
What can be used as an estimate of an athletes relative training intensity
measurement of exercise HR
What is the equation for calculating VO2 max
VO2max = (HR max * SVmax) * max (a-v) O2 difference
HR * SV = Q
What happens to cardiac output with training
untrained = plateau at about 20 L/min
trained = plateau at 27 L/min
more Q after training