Energy Transfer During Exercise

Question 1

Describe the quantity of ATP in the body. How is energy transferred?

Answer 1

ATP is NOT stored in large quantities in the body

-Human energy dynamics involves transferring energy by CHEMICAL BONDS

Question 2

Why is Phosphocreatin (PCr) useful?

Answer 2

Phosphocreatine (PCr)- phosphates- energy reservoir. PCr can donate its phosphate group and convert ADP into ATP.
NO O2 is required, and its maximum energy yield is in 10 secs
it is a great molecule that regenerates ATP supply (since ATP is in short supply)
occurs naturally in skeletal muscles.

Question 3

What are the three energy transfer systems?

Answer 3

The three energy transfer systems:

1. ATP-PCR system
2. Lactic Acid system
3. Aerobic system

Question 4

What is a phosphagen?

Answer 4

Phosphagen- high energy storage molecules (Store high energy phosphate) that are found in muscle and nerve tissue of animals
they are great reserve of high energy phosphates that can be used to make ATP
ex; PCr (phosphocreatine) is a great example of phosphagen

Question 5

What kind of free energy level is ATP? Explain why.

Answer 5

ATP is an intermediate level of free energy due to the benefit of being able to donate a phosphate group to a number of substrates with lower free energy and also having some higher free energy substrates that can donate phosphate to ADP and make ATP.
Ex: Phophrocreatine or PEP (phosphoenolpyruvate) is a higher free energy molecule than ATP. whereas Glucose, 1- phosphate or glucose 6-phosphate are lower free energy molecules.

Question 6

Describe what occurs in ATP-PCR system/ what kind of energy transfer is this?

Answer 6

ATP-PCR System (IMMEDIATE Energy; 5-8 sec)- Anaerobic

• High intensity exercise of short duration (100-m dash, 35-m swim, lifting a heavy weight) requires immediate energy from intramuscular ATP and PCr.
• Each kg of skeletal muscle contains 3-8 mM of ATP and 4-5 times more PCr.
• Maximum rate of energy transfer from intramuscular phosphagens EXCEEDS the maximum transfer aerobic by 4-8 times

Question 7

which sports rely exclusively on energy transfer of high energy phosphate?
What occurs during the big muscle exercise?
What occurs to energy transfer for an athlete like Usain bolt?

Answer 7

While all movements use high-energy phosphates as an energy source, some sports rely exclusively on this energy transfer (football, baseball, weight lifting)
Big muscle exercise- 20 kg skeletal muscle activated- phosphagen energy can supply energy for brisk walk for 1 min, marathon pace for 20-30 secs and sprint running for 5-8 secs
Usain bolt has 100m record of 9.58 secs but still CANNOT maintain max speed the entire run. He has to switch from immediate ATP and PCR to anaerobic lactic acid system eventually.

Question 8

What happens to ATP and PCR system during continuation of strenuous exercise?

Answer 8

Continuation of strenuous exercise
-energy transfer rate from high-energy phosphate (45%) will switch to energy primary from ANAEROBIC GLYCOLYSIS
Anaerobic glycolysis- allows for rapid formation of ATP, even though O2 supply is inadequate and or energy demands outstrip the muscle’s capacity to resynthesize ATP.
-reserve fuel

Question 9

How long is ATP solely used for and what kind of physical activity uses this?
what about ATP and PCR, ATP + PCR + Lactic Acid and ETC- Oxidative Phosphorylation

Answer 9

Solely ATP can be used for 4s for STRENGT-POWER activity like a power lift, high jump, javelin throw, golf swing or tennis serve
ATP + PCR- SUSTAINED power for 5-8 secs like sprints, football line play, gymnastics
ATP + PCR + lactic acid for 10 secs -1.5 mins like (200-400 m dash, 100 m swim)
Electron Transport-Oxidative Phosphorlyation- Aerobic endurance for after 1.5 mins (beyond 800 m run)

Question 10

Describe what occurs in the Lactic Acid System (Short-Term Energy). Where is this energy source coming from and when does lactate accumulate?
What can decrease rate of lactate accumulation?

Answer 10

Lactic Acid System (short-term Energy)
Energy to phosphorylate ADP during INTENSE, short-duration exercise comes mainly form STORED MUSCLE GLYCOGEN BREAKDOWN via anaerobic glycolysis with resulting LACTATE formation
rapid and large accumulations of blood lactate occur during maximal exercise that lasts between 60-180 secs
Decreasing the intensity of exercise to extend the exercise period correspondingly decreases the rate of lactate accumulation and the final blood lactate level

Question 11

When does blood lactate accumulate?

Answer 11

Blood lactate accumulates when REMOVAL does NOT match production
this occurs when lactate appearance is higher (outweighs) than lactate disappearance
Pyruvate converts to Lactate by LACTATE Dehydrogenase and generates NAD+

Question 12

Does blood lactate accumulate at all levels of exercise? Explain

Answer 12

Blood lactate does NOT accumulate at all levels of exercise.
During light and moderate exercise (less than 50% aerobic capacity ) blood lactate production = lactate disappearance and O2-consuming reactions adequately meet the exercise energy demands.
hence lactate does NOT accumulate with light and moderate exercise

Question 13

Discuss blood lactate concentration in trained vs untrained individuals. What factors are related to lactate threshold?

Answer 13

for healthy, untrained individuals, blood lactate begins to accumulate and rise in exponential fashion at about 50-55% of max capacity for aerobic metabolism
where as trained individuals blood lactate begins to accumulate at 75% max capacity (VO2 max)
factors related to lactate threshold:
-low tissue oxygen
-reliance on glycolysis
-activation of fast-twitch muscle fibers
-reduced lactate removal

Question 14

compare and contrast fast twitch fibers and slow-twitch fibers

Answer 14

Fast twitch fibers: are more powerful, more responsive, more dependent on anaerobic respiration and creates more lactate and leas to fatigue.
Slow-twitch fibers: do not fatigue as quickly, use aerobic respiration

Question 15

What is blood lactate threshold? What does it describe and how does it differ in trained vs untrained individuals?

Answer 15

Blood lactate threshold- occurs when muscle cells can neither meet the additional energy demands aerobically nor oxidize lactate at its rate of formation
lactate threshold describes when lactate appearance is greater than lactate disappearance
blood lactate threshold occurs at a HIGHER percentage of TRAINED athlete’s aerobic capacity compared to untrained individuals.
-one can perform steady rate aerobic exercise at 80-90% of Maximum capacity for aerobic metabolism due to
-athlete’s genetic endowment
-specific local training adaptations that favor less lactate production
-more rapid rate of lactate removal at any intensity.

Question 16

Describe what occurs in the Aerobic System (Long-Term Energy)? What is steady rate?

Answer 16

Aerobic System (Long-Term Energy)
-Aerobic metabolism provides nearly ALL of the energy transfer when intense exercise continues beyond Several minutes (after 1.5 mins)
- Oxygen consumption rises exponentially during first minutes of exercise before it plateaus and remains relatively stable for duration of effort
Steady rate reflects a balance between energy required by working muscles and ATP production in aerobic metabolism.
NO appreciable BLOOD LACTATE accumulates under steady-rate metabolic conditions.

Question 17

Describe Oxygen consumption during exercise

Answer 17

O2 consumption depends on how trained you are. There are different steady rates during exercise which depend on how close you are to max O2 capacity.
trained individuals reach steady rate faster than untrained individuals.

Question 18

What are the limits of steady rate aerobic metabolism?

Answer 18

Steady rate exercise could theoretically progess indefinitely, assuming that steady-rate aerobic metabolism determines the capacity to sustain submaximal exercise

limitations:
- fluid loss and electrolyte depletion
- Maintaining adequate reserves of both liver glycogen for central nervous system function and muscle glycogen to power exercise

Question 19

What is the determination of steady rate levels?

Answer 19

Determination of steady rate levels
individuals possess many steady-rate levels of exercise
-exceptional endurance accomplishments result from:
-high capacity of the central circulation to deliver oxygen to working muscles
-high capacity of exercised muscles to use available oxygen

Question 20

What is oxygen deficit and what does it represent?

Answer 20

Oxygen deficit- quantitatively expresses the difference between the total oxygen consumption during exercise and the total. that would be consumed had steady-rate O2 consumption been achieved from the start

• represents the immediate anaerobic energy transfer from hydrolysis of intramuscular high-energy phosphates and glycolysis until steady-rate energy transfer matches energy demands.
• energy for exercise does not simply occur from activating a series of energy systems that Switch on and switch off, but rather from smooth blending with considerable overlap of one mode of energy transfer to another.

Question 21

Compare and contrast the oxygen deficit in trained vs untriained individuals

Answer 21

Endurance-trained individuals reach steady rate more RAPIDLY and have SMALLER oxygen deficit than sprint-power athletes, cardiac patients, older Adults, or untrained individuals
-untrained individuals- have higher O2 deficit and take a longer time to reach steady rate
A faster aerobic kinetic response allows the trained person to consume a greater total amount of oxygen to steady-rate exercise and makes the anaerobic component of exercise energy transfer proportionately smaller.

Question 22

What is maximal oxygen consumption?

Answer 22

Maximal Oxygen Consumption- when oxygen consumption plateaus or increases slightly with additional increases in exercise intensity.
-provides a quantitative measure of a person’s capacity for aerobic ATP resynthesis
one factor in the ability to sustain intense exercise for longer than 4 or 5 minutes and has a role in sustaining energy metabolism
-also called maximal oxygen uptake, maxima aerobic power, aerobic capacity or VO2max.

Question 23

Describe what occurs in the maximal oxygen consumption while running up hills

Answer 23

As you increase the grade of hills (go up more hills), you o2 consumption will increase and eventually plateau around grade 6, towards reaching Vo2 max.

Question 24

Describe the percentage of aerobic vs anaerobic when it comes to total energy yield .

Answer 24

aerobic will kick in faster in terms of higher energy percentage yield compared to anaerobic
in first 60 seconds of max exercise, anaerobic percentage dominates
during 2 minutes of max exercise, anaerobic and aerobic percentages are 50, 50.
after 4 minutes of max exercise- Aerobic dominates

Question 25

what kind of energy source is predominately used for 100m , 200-400m, 24 hr race and soccer.

Answer 25

100m yes 50, 50 anaerobic and aerobic
200-400 m uses predominant anaerobic (lactic acid)
soccer uses predominantly 70$ anaerobic

Question 26

Why is there 88% fatty acid used in 24 hour race?

Answer 26

There is 88% fatty acid used because you’re running at low intensity and in fat burning zone. you are burning fats for fuel

Question 27

Describe th factors that lead to facilitated rate of aerobic metabolism.

Answer 27

A facilitated rate of aerobic metabolism in the beginning of exercise with aerobic training occurs from:

• a more rapid increase in muscle bioenergetics
• an increase overall blood flow
• a disproportionately large regional blood flow to active muscle complemented by cellular adaptations
• many of these adaptations increase capacity to generate ATP aerobically.

Question 28

Describe oxygen consumption in recovery

Answer 28

Oxygen consumption in Recovery
-how rapidly an individual responds in recovery light, moderate or strenuous exercise depends of specific metabolic and physiologic processes during and in recovery form each type of effort
moderate to intense aerobic exercise requires a LONGER time to achieve steady state, which creates a LARGER oxygen deficit than less-intense exercise
It takes longer for recovery oxygen consumption to return to pre-exercise level.
low intensity- easier to reach steady state
moderate intesity- higher O2 deficit, during recovery
High intesnity- even higher O2 deficit and even higher O2 consumption

Question 29

What is Oxygen debt? What are other words used to describe it? What are the characteristics of it?

Answer 29

oxygen debt, aka recovery oxygen consumption or EPOC (excess- post-exercise Oxygen consumption)- describes the total oxygen consumed in recovery minus total oxygen theoretically consumed at rest during recovery period
Characteristics of recovery oxygen consumption:
-Fast component: with mild aerobic exercise of short duration, 1/2 of total recovery oxygen consumption occurs within 30 seconds and complete recovery within minutes
-Slow component: recovery from strenuous exercise includes fast component of recovery as well as the slow component that can take up to 24 hours

Question 30

How does EPOC and and different exercise duration relate?

Answer 30

The longer people walked for treadmills (longer duration), the higher the EPOC and the more O2 consumption.

Question 31

what are the implications for EPOC for Exercise and recovery?

Answer 31

Implications for EPOC for Exercise and recovery:

• no appreciable lactate accumulates with steady-rate exercise or brief 5-10 second bouts of all-out effort, so recovery progresses rapidly and exercise can begin again with only short rest period and passive recovery.
• prolonged duration of anaerobic exercise produce considerable lactate buildup so recovery oxygen consumption requires considerable time to return baseline
• athletes pushed to high level of anaerobic metabolism may not fully recover during brief time-out periods or intermittent intervals of less-intense exercise.

Question 32

Compare and contrast active and passive recovery?

Answer 32

Active recovery- also called Cooling down or tapering-off; the individual performs submaximal exercise presuming that continued physical activity prevents muscle cramps, and stiffness and facilitates overall recovery
Passive recovery- the persons usually lies down, presuming that TOTAL INACTIVITY reduces the resting energy requirements and thus frees oxygen to fuel recovery process; modifications include massage, cold showers, specific body positions, and consuming liquids.

Question 33

Compare the difference in blood lactate concentration following maximal exercise in passive and active recoveries.

Answer 33

Active recovery at 35-65 VO2 max will be better at clearing lactate than passive recovery.
However using 65% max O2 consumption is too much, and will cause lactate to accumulate.

Question 34

Describe the optimal recovery from steady-rate exercise. What occurs during recovery?

Answer 34

Most individuals exercise in steady rate with little lactate accumulation at 55 to 60% VO2 max.
recovery entails resynthesis of high-energy phosphates, replenishment of Oxygen in the blood, bodily fluids and myoglobin, and a small energy cost to sustain elevated circulation and ventilation .
Passive procedures facilitate recovery because any additional exercise under these circumstances only serves to elevate total metabolism and delay recovery.

Question 35

explain how to measure VO2 max

Answer 35

you can use VO2 test that occurs when person is exercising (walking a treadmill or riding bike)
Person will attach chest strap of heart monitor and attack a mask to a person’s mouth to capture all of O2 that is taken in),. there will be a hose that will capture CO2 that one breaths out. As you are exercising heart rate is also being monitored
-the more O2 taken in during exercise, the more O2 that goes to muscles, and allows you to work muscle more.
bigger the VO2, the better.

Question 36

what are benefits of EPOC?

Answer 36

Benefits of EPOC:
Resynthesize ATP and PCr
-resynthesize lactate to glycogen (cori cycle)
oxidize lactate in energy metabolism
-restore oxygen to myoglobin and blood
-thermogenic effects of elevated core temperature
-thermogeneic effects of hormone (catecholamines)
-Effects of elevated heart rate, ventilation and other physiologic functions.