Overview of Bioenergetics Lesson

Interaction of the Energy SystemsInteraction of the Energy Systems How Energy Systems work togetherHow Energy Systems work together Looking at the Energy Systems Looking at the Energy Systems

at restat rest

at the beginning of exerciseat the beginning of exercise

during steady state exerciseduring steady state exercise

during strenuous exerciseduring strenuous exercise

during recoveryduring recovery

3 Energy Systems Working Together At rest: small amounts of energy are used small amounts of energy are used

At the Beginning of Exercise: If the energy system is If the energy system is slightly higher than rest, the aerobic system continuesslightly higher than rest, the aerobic system continues

If the energy demand is immediate and high, stored energy If the energy demand is immediate and high, stored energy or ATP is usedor ATP is used

CP can also help to create more energy anaerobically until CP can also help to create more energy anaerobically until the aerobic system catches up the aerobic system catches up

After 20-30 seconds glycolysis kicks inAfter 20-30 seconds glycolysis kicks in

Energy Systems ContinuedThe volume of oxygen missing in the first few minutes of

exercise is the oxygen deficitoxygen deficit

During Steady State Exercise: During Steady State Exercise: Once the supply of oxygen meets the demand…. the muscle cell creates ATP using the breakdown of glucose through the oxidation system

Oxygen uptake and heart rate level off, energy demands and energy production are balanced…steady level of exertion for an extended period of time

During Strenuous Exercise: During Strenuous Exercise: If energy demand is rapid and extended the energy demand will require the anerobic system to provide ATP

3 Energy Systems Continued:

Once ATP-CP is fatigued, the glycolytic Once ATP-CP is fatigued, the glycolytic system takes oversystem takes over

Fatigue or failure may result if oxygen Fatigue or failure may result if oxygen demand exceeds supply and high intensity demand exceeds supply and high intensity exercise continues beyond 2 minutesexercise continues beyond 2 minutes

ThTThT

The red area reflects ATP production by the The red area reflects ATP production by the aerobic systemaerobic system

Within 3-5 min, the VOWithin 3-5 min, the VO22 reaches a steady state reaches a steady state

indicating that the aerobic system is supplying indicating that the aerobic system is supplying all the energy required by the muscles. all the energy required by the muscles.

The area indicated by OThe area indicated by O22D in the above figure D in the above figure

is defined as the is defined as the oxygen deficitoxygen deficit and reflects and reflects energy supplied to the muscles by non-aerobic energy supplied to the muscles by non-aerobic systems.systems.

3 Energy Systems Continued:

During Recovery: During Recovery: After exercise the body continues to take in more oxygen then it needs

The “surplus” of oxygen is thereby available to pay off the debt of oxygen that occurred at the beginning of exercise

This oxygen is known as Excess Post Exercise Excess Post Exercise Oxygen Consumption (EPOC) Oxygen Consumption (EPOC)

After cessation of exercise, VOAfter cessation of exercise, VO22 doesn't doesn't

immediately return to resting levels, rather, immediately return to resting levels, rather, VOVO22 makes a gradual decrease even though makes a gradual decrease even though

energy demands are only at resting levels.energy demands are only at resting levels.

The elevated VOThe elevated VO22 during exercise recovery, during exercise recovery,

and the amount of EPOC is usually greater and the amount of EPOC is usually greater than the amount of the Othan the amount of the O22 deficit (compare deficit (compare

the areas of the Othe areas of the O22 deficit and EPOC in the deficit and EPOC in the

Figure ). Figure ).

ThTThT

What is EPOC used for?

EPOC is used for ATP and CP EPOC is used for ATP and CP replenishmentreplenishment

If the activity was more anaerobic or If the activity was more anaerobic or intense..then the greater the oxygen deficit intense..then the greater the oxygen deficit and more EPOC is required to return the and more EPOC is required to return the body to a pre exercise statebody to a pre exercise state

Other Factors of EPOC

Temperature recoveryTemperature recovery Heart Rate recoveryHeart Rate recovery Ventilation recoveryVentilation recovery Hormone recoveryHormone recovery

Review of the 3 Systems

All systems are working at the same time All systems are working at the same time There is a predominance of one system over another There is a predominance of one system over another

depending on the intensity of the activity depending on the intensity of the activity