understanding exercise systems Flashcards
various processes of energy/macronutrient use within the body and the function of energy systems for fuel provision during exercise
bioenergetics
the quantity of force produced is a factor of _____- less time=____ force capabilities
time under tension
greater
the duration of time under tension is a factor of _____- longer time =____ force capabilities
force produced
lower
different energy sources are used as the duration of time under tension ____
increases
immediate energy (ATP and phosphates) ___sec
<15
intermediate energy (glycolytic)
____ sec
<90
continuous energy (aerobic) ____min
> 3
_____ occurs as these energy systems blend together in sequence over time
signaling overlap
only energy source to fuel the “power stroke” that drives muscle contraction
ATP
ATP located ____ muscle
inside
ATP is ready to use for ____ needs during ________
immediate, maximal effort and powerful work
ATP fuels maximal muscular work lasting ____ sec
1-3 sec
ATP rest periods of ____ sec allow for full recovery
90
ATP is broken down by ____ to liberate a phosphate ion producing energy- ___ is a byproduct
ATPase, ADP
ATP reaction
ATP + H20 <–> ADP + Pi + energy
phosphates system
ATP depletes so rapidly so an additional pool go high-energy phosphate storage is maintained in the form of creatine phosphate
organic compound capable of storing and providing high energy phosphate elements to fuel muscular contractions
creatine phosphate
creatine phosphate reuse ATP store to continue
short, powerful bursts of work lasting around 10-15 sec
creatine phosphate recovery ranges from ___ mins depending on the activity and volume
2-5
creatine kinase reaction
CP + ADP <–> C + ATP
work lasting longer than 10-15 seconds requires the body to metabolize ____ and ____ anaerobically to maintain adequate ATP production
glucose, glycogen
glucose
simple sugar molecule that is the primary source of metabolized fuel for the glycolytic energy system
glycogen
storage form of carbohydrates (CHO) in the body metabolized to provide glucose
glycogen storage sites
skeletal muscle 300-400g and the liver 75-100g
glycolysis supports moderate-intensity work for ___ sec and contributes to the ____ system
90, aerobic
_____ and ____ are created as byproducts of glycolysis as well as the release of ____ ions
lactic acid, pyruvate, H+
the H+ eventually promotes ___ and the acidity shuts off the enzymes inhibiting contractions
ischemia
lactic acid
lactate; used by various tissues to fuel continuous work; serves as an initial buffer for H+ created by anaerobic glucose metabolism
end product of sugar metabolism during glycolysis in the presence of oxygen
pyruvate
pyruvate is broken down further to provide
ongoing aerobic energy through the Krebbs cycle
ischemia
low oxygen state caused by tissue acidity (via H+ or otherwise), obstruction of arterial blood supply, or inadequate blood flow to a region
primary culprit behind “burning” sensation and inability to work at the end of a glycolytic-driven exercise
H+
during intense work, ischemia occurs as excess hydrogen builds up, leading to a drop in pH that may:
1. limit ____ reactions
2. alter ____ handling
3. leading to ________
enzymatic
calcium
intrinsic muscle fatigue
____ has been blamed for DOMS
lactate
lactate actually helps maintain
energy levels during intense glycolytic work
lactate is used in immediate recovery in
metabolic organs and the heart
H causes ischemia when ____ is inadequate to support buffering
oxygen
lactate buffers ___ and is shuttled to various tissues via bloodstream to aid in ______
H+, gluconeogenesis
gluconeogenesis
creation of new glucose
DOMS
muscle soreness expedited by an inflammatory response due to cellular damage, ischemia and tonic spasms
when does DOMS occur
24-72 hours following an intense bout of exercise
what increase the response of DOMS
new exercise, heavy eccentric, high work volume
energy systems interact more than they function in a _____ fashion
segregated
when oxygen use matches demand, _____ has been achieved
metabolic steady state
steady state
signified by a leveling off or steady heart rate of no more than +/- 5bpm
when the body transitions between metabolic systems, working tissues experience ___ deficit
oxygen
oxygen deficit
anaerobic demands must be “paid back” after work is discontinued to bring the body back to resting homeostasis, resulting in an evaluation in oxygen consumption after exercise discontinues
oxygen debt must be repaid after exercise to attain
resting homeostasis
EPOC
excess post-exercise oxygen consumption
increase in the rate of oxygen consumption following strenuous activity due to a deficit created by the work
the intensity of exercise and caloric expenditure is clinically measured via
mets
METs
multiples of the resting metabolic rate; one MET equals an oxygen reuptake rate of 3.5 ml of O2 per kg of body weight per min
aerobic system
metabolic pathway where the mitochondrion utilizes substrates of fats, CHO, and protein to produce ATP in the presence of oxygen
glycolysis from glycolysis sparks the Krebs cycle within the mitochondria to initiate the process of using all available energy sources, signaling the body needs ______ which causes the release of _____ to breakdown ____ and ____
more energy, adrenal hormones, fat and protein
Krebs cycle
series of enzymatic reactions involving aerobic metabolism of compounds which produce significant ATP
aerobic metabolism fuels ongoing efforts lasting ___ min
> 3
as fat use for fuel is greatest during _____ intensity exercise via aerobic metabolism
lower
fat burning zone
lower intensity training (<65% VO2 max) where the predominant fuel source is fat
the fat burning zone is not optimal weight loss method because
the relative quantity total calories burned is too low compared to higher intensities
FatMax
highest intensity of work performed where fat is the primary source of fuel
FatMax lies between ____ % VO2 max
60-70
the major reason behind why only lower intensities can be fueled via aerobic sources
the speed by which the body can liberate triglycerides from fat
an enzyme known as _____ liberates fatty acids from triglycerides composed of a glycerol backbone for use as fuel
lipase
anaerobic system:___ 1-3 sec –> ___ 5-10 sec–>____ up to 3 min
ATP, CP, glycolysis
aerobic system: ____ + ____ or ____
oxygen, fats, glucose
each energy pathway determines
_____ of potential force
_____ of potential force
total force produced from ______
____ associated with system recovery
magnitude, sustainability, energy system as a whole, rest interval
fatigue sets in when the body experiences a significant decline in ____ along with elevated____
muscle and liver glycogen stores, byproduct concentrations within working muscles
energy depletion is related to intensity as it
dictates the demand for fuel and the rate of byproduct production
low intensity exercise = primarily sustained by
lipid metabolism, glycogen is minimal
elevated intensity or intermittent high intensity exercise = glycogen is
rapidly depleted
_____ are vital to performance and maintaining lean mass
CHO
intense work requires CHO as they can be
metabolized much faster than fats
protein-sparing is facilitated as ____ is adequate and the liver maintains ________
blood glucose, higher stores of glycogen
if glycogen is depleted the body is forced to metabolize ______ liberated from muscle tissue to maintain blood glucose for the CNS
branched-chain amino acids
even at levels where oxygen and lipids are adequate to meet the demands of work, a lack of CHO will cause
significant fatigue, reduced performance and protein catabolism
branched-chain amino acids include (3)
leucine, isoleucine, valine
BCAAs serve as
potential fuel source during long-duration exercise bouts, especially with inadequate CHOs
3 types of fatigue
acute peripheral, general peripheral, central
cells experience dysfunction due to acidity which limits enzyme activity, requiring buffering compounds and a rest period before work can be re-initiated
acute peripheral fatigue
occurs with a lack of energy in working tissues due to low pre-exercise stores or localized depletion of anaerobic sores from activity
general peripheral fatigue
in general peripheral fatigue, acute rest intervals will not help, ____ is needed
recovery period
occurs with systemic depletion of CHOs, resulting in reduced motor unit recruitment and firing rate
central fatigue
central fatigue reflects a conscious and subconscious decision to
reduce the intensity of exercise until energy replenishment and/or recovery have provided fuel for the re-initiation of work
rest periods
period between sets or structured periods of activity within a single exercise bout
the length of rest periods is dictated by
energy systems involved during the sets of work
recovery period
period of time in between separate exercise bouts so adaptations may occur
cellular permeability and heightened hormone sensitivity allow for
increased glycogen storage and protein use in the 3-hour period following exercise
higher _____ foods are recommended within the prime metabolic window (45min)
glycemic
post exercise muscle glycogen can be further enhanced with ____ ratio or supplement
CHO/protein meal (3-4:1)
Which of the following energy sources fuels maximal-effort muscular work lasting 1-3 seconds, such as a vertical jump?
a. Creatine phosphate
b. Glycogen
c. ATP
d. Pyruvate
c
The phosphagen system would be the primary energy system utilized during which of the following:
a. Set of bicep curls for 15 repetitions
b. Running a 10K
c. 20 minutes of circuit training
d. 3RM back squat
d
Which of the following can be used as fuel by various tissues, including the heart, and helps to buffer tissue acidity during anaerobic training?
a. Glucose
b. Lactate
c. Pyruvate
d. Glycogen
b
Which of the following is incorrect concerning the fat-burning zone?
a. It is an optimal method for maximizing weight loss
b. It requires lower-intensity aerobic training <65% of VO2max
c. It allows for a maximal relative quantity of calories burned to come from fat
d. It is associated with an individual’s FatMax
a
Which of the following describes a reason why carbohydrates are vital to performance?
a. Intense work requires carbohydrate metabolism over fat
b. Adequate carbohydrate intake spares bodily proteins from being pulled from muscles
c. Carbohydrates are the limiting factor for central fatigue
d. All of the above are correct
d
True or False? The glycolytic system supports moderate-intensity work lasting up to 90 seconds.
true
True or False? Energy systems interact and transition smoothly to continue performing work rather than working in a segregated fashion.
true
True or False? The aerobic system can maintain energy production until fat stores are depleted as a limiting factor to ATP production.
false
True or False? Post-exercise glycogen storage can be optimized with a meal or supplement containing a 1:1 carbohydrate-protein ratio.
false
____relates to the increase in oxygen consumption and caloric expenditure for hours following strenuous activity due to an oxygen deficit created during the bout
excess post-exercise oxygen consumption
Ischemia and the burning sensation that progressively occurs at the end of an anaerobic set is due to the accumulation of _____ within the working tissues.
hydrogen ions
____ periods are used between sets of exercise while ____ periods are used in between separate exercise bouts to allow for adaptations
rest, recovery
Identify the energy system used for each of the following.
a. Immediate energy:
b. Intermediate energy:
c. Continuous energy:
ATP and phosphagen
glycolysis
aerobic system
Identify the two primary storage sites for glycogen.
liver, skeletal muscle
Define the mechanism for each of the following.
a Acute peripheral fatigue
b General peripheral fatigue
c Central fatigue
a. cells experience dysfunction due to acidity which limits enzyme activity, requiring buffering compounds and a rest period before work can be re-initiated
b. occurs with a lack of energy in working tissues due to low pre-exercise stores or localized depletion of anaerobic stores from activity; acute rest intervals will not help, a recovery period is needed
c. occurs with systemic depletion of CHOs, resulting in reduced motor unit recruitment and firing rate; reflects a conscious and subconscious decision to reduce the intensity of exercise until energy replenishment and/or recovery have provided fuel for the re-initiation of work (hitting the wall – additional exercise is futile)
