Chapter 3: Bioenergetics of Exercise and Training Flashcards
flow of energy in a biological system, process that converts macronutrients into usable forms of energy to perform work
bioenergetics
what is metabolic specificity of training?
the concept that appropriate intensities and rest intervals can permit the selection of specific primary energy systems during training for specific athletic events
metabolism
total of all the catabolic and anabolic reactions in a biological system
catabolism
breakdown of large molecules into smaller molecules with the release of energy
anabolsim
synthesis of a large molecule from smaller molecules that requires energy released from catabolic reactions
energy-releasing reactions that are generally catabolic
exergonic reactions
reactions that require energy, include anabolic processes and the contraction of muscle
endergonic reactions
molecule that allows the transfer of energy from exergonic to endergonic reactions
ATP
hydrolysis
the breakdown of one molecule of ATP to yield energy
3 basic energy systems to replenish ATP
phosphagen
glycolysis
oxidative
processes that do not require oxygen
anaerobic
processes that depend on oxygen
aerobic
2 anaerobic energy systems that occur in the sarcoplasm of the muscle cell
phosphagen and glycolytic systems
2 aerobic mechanisms that occur in the mitochondria of muscle cells and require oxygen
kreb’s cycle and oxidative system
what is the only macronutrient that can be metabolized for energy without the direct involvement of oxygen and critical during anaerobic metabolism?
carbohydrate
energy system that provides ATP primarily for short term, high intensity activities and is highly active at the start of all exercise regardless of intensity
phosphagen system
which muscle fiber type contains higher concentrations of CP and can therefore replenish ATP faster through the phosphagen system during anaerobic explosive exercise?
type II fast twitch
energy system that uses the breakdown of carbohydrates to resynthesize ATP (either glycogen stored in the muscle or glucose delivered in the blood)
glycolysis
anaerobic glycolysis (fast)
when pyruvate is converted to lactate, ATP resynthesis occurs at a faster rate but is limited in duration
aerobic glycolysis (slow)
when pyruvate is shuttled into the mitochondria to undergo the kreb’s cycle, ATP resynthesis rate is slower but can occur for a longer duration if exercise intensity is low enough
true or false: lactate is the cause of muscle fatigue
false
metabolic acidosis
process of an exercise induced accumulation of H+ that may be responsible for much of the fatigue that occurs during exercise
causes fatigue by reducing pH, inhibiting glycolytic reactions, and interfering with the muscle’s excitation-contraction coupling
H+
what is the cori cycle?
process where lactate is transported in the blood to the liver to be converted to glucose
end result of glycolysis
pyruvate
A series of reactions that continues the oxidation of the substrate from glycolysis and produces 2 ATP molecules is known as
Krebs cycle
what energy system uses carbs and fats as the primary source of ATP at rest and during low intensity activities?
oxidative system
what is lactate threshold?
the exercise intensity at which blood lactate begins an abrupt increase above the baseline concentration, increased reliance on anaerobic mechanisms
what is the typical lactate threshold for untrained individuals?
50-60% of maximal oxygen uptake
what is the typical lactate threshold for trained individuals?
70-80% of maximal oxygen uptake
what is the onset of blood lactate accumulation (OBLA)?
occurs when the concentration of blood lactate reaches 4mmol/L, usually during high intensity exercise
what type of muscle fiber produces lactate?
type IIa and type IIx
what type of muscle fiber oxidizes lactate?
type I
why is training near LT and OBLA important?
it allows the athlete to work at higher intensities with less fatigue
how many net ATP are produced via the oxidative energy system from the metabolism of one glucose?
38
what energy system produces ATP at the quickest rate but shortest duration?
phosphagen system
what energy system produces ATP at the slowest rate but longest duration?
oxidative system
how many ATP are produced via slow glycolysis?
2 net ATP
a method that emphasizes bioenergtic adaptations for a more efficient energy transfer by using predetermined work to rest ratios
interval training
brief repeated bouts of high intensity exercise with intermittent recovery periods
HIIT
process of anaerobic glycolysis
pyruvate gets converted to lactate
process of aerobic glycolysis
glucose converted to pyruvate
pyruvate goes to the mitochondria
pyruvate undergoes Krebs cycle
What are the three ways blood sugar can be stored?
-glycogen storage (liver/muscles)
-fat storage
-energy (glucose)
oxygen uptake above resting values used to restore the body to the pre exercise condition
EPOC
total energy cost of exercise
oxygen deficit
Excess Post Exercise Oxygen Consumption is also known as oxygen ________ or recovery __________
debt; O2
what type of mechanism provides much of the energy for work if the exercise intensity is above the maximal oxygen uptake?
anaerobic mechanisms
the process of ATP hydrolysis results in what 3 things?
ADP
H+
energy
why does energy come from anaerobic mechanisms at the start of exercise?
aerobic system responds slowly to the initial increase in the demand for energy
energy systems depend on what two aspects of training with program design?
primarily: level of intensity
secondarily: duration
what percentage of power is the phosphagen system primarily used for?
90-100%
process of cutting a glucose molecule in half that happens outside the mitochondria
glycolysis
what energy system is being used when walking?
aerobic glycolysis (slow)
true or false: glycolysis requires oxygen
false
process of making new glucose molecules
gluconeogenesis
what are 2 examples of catecholamines that are released to increase blood sugar?
epinephrine and norepinephrine
fat burning system that produces a greater amount of ATP but takes longer
beta oxidation
true or false: higher intensity training has a higher EPOC
true
if you accumulate oxygen debt/deficit during exercise, you will pay it back after the workout in the form of what?
EPOC
what fuel source is used for energy production during rest?
70% fats, 30% carbs
what energy systems are used for energy production at rest?
aerobic glycolysis
Krebs cycle
oxidative phosphorylation
what energy system will you use for running a marathon?
oxidative (50% fats, 50% carbs)
what energy system is used during interval training?
anaerobic glycolysis and oxidative
what fuel source is used during high intensity exercise?
~ 90% carbs
adds aerobic endurance training to the training of anaerobic athletes in order to enhance recovery
combination training
what is the importance of interval training?
much more training can be accomplished at higher intensities
the rate of glycogen depletion is related to what?
exercise intensity
at what intensity % of exercise does muscle glycogen become an increasingly important energy substrate?
60% of maximal oxygen uptake
how many grams of carbs per kg of body weight should be ingested 2 hours following exercise for optimal repletion of muscle glycogen?
0.7 to 3.0g
how does repletion of muscle glycogen occur during recovery?
post exercise carbohydrate ingestion
work to rest period ratio for phosphagen system at 90-100% power
1:12 to 1:20
work to rest period ratio for aerobic glycolysis at 75-90% power
1:3 to 1:5
work to rest period ratio for fast glycolysis and oxidative systems at 30-75% power
1:3 to 1:4
work to rest period ratio for oxidative system at 20-30% power
1:1 to 1:3
