Exercise Physiology:Exercise Physiology:

physiology: the sum of all biologic physiology: the sum of all biologic processesprocesses

what happens to these processes when what happens to these processes when exerciseexercise

Metabolism: sum total of all Metabolism: sum total of all processes occurring in living processes occurring in living

organismsorganisms catabolism: breakdowncatabolism: breakdown

anabolism: build upanabolism: build up

Energy transductions or Energy transductions or conversions are limited by the conversions are limited by the

laws of thermodynamicslaws of thermodynamics

Energy is transferred or Energy is transferred or convertedconverted

food converted to fatfood converted to fat light and COlight and CO22 make sugar make sugar

Measured in kilocaloriesMeasured in kilocalories

amount of energy necessary to raise the amount of energy necessary to raise the temperature of 1 lit of water one degree temperature of 1 lit of water one degree CelsiusCelsius

Energy then, is related to the Energy then, is related to the ability to perform workability to perform work

Can measure the capacity for Can measure the capacity for maximal work capacity in manmaximal work capacity in man

via exercise physiologyvia exercise physiology

11stst law of thermodynamics: law of thermodynamics:

energy is neither created nor destroyedenergy is neither created nor destroyed it is converted or transformed from one form it is converted or transformed from one form

to anotherto another

Energy can be categorized asEnergy can be categorized as

potential energy (amount of energy in canoe potential energy (amount of energy in canoe on top of falls)on top of falls)– can be light, electric, or bound can be light, electric, or bound

kinetic energy (amount of energy in canoe at kinetic energy (amount of energy in canoe at the bottom of falls)the bottom of falls)– energy of motionenergy of motion

Energy-releasing and Energy-Energy-releasing and Energy-conserving processesconserving processes

must be coupledmust be coupled exergonic processes release or “frees” exergonic processes release or “frees”

energyenergy– downhilldownhill

endergonic processes release of “store” endergonic processes release of “store” energyenergy– uphilluphill

Transfer of potential energy is Transfer of potential energy is unidirectional, to kinetic unidirectional, to kinetic

energy, lowering the energy to energy, lowering the energy to do workdo work

This parallels the second law of This parallels the second law of thermodynamics:thermodynamics:

potential energy gradually decreases, potential energy gradually decreases, entrophy increasesentrophy increases

the reactions in the body move towards the reactions in the body move towards spontaneity, disorder, and randomnessspontaneity, disorder, and randomness

Energy conversionsEnergy conversions

photosynthesisphotosynthesis respiration (part of energy converted can be respiration (part of energy converted can be

utilized for different work in the human body)utilized for different work in the human body)

Biologic work in humans: Biologic work in humans: BioenergeticsBioenergetics

mechanical (muscle contraction)mechanical (muscle contraction) chemical (biosynthesis of cellular chemical (biosynthesis of cellular

molecules)molecules) transport (concentrating chemicals in intra transport (concentrating chemicals in intra

and extracellular fluids)and extracellular fluids)

Factors affecting the rate of Factors affecting the rate of bioenergetics:bioenergetics:

enzymesenzymes coenzymescoenzymes mass actionmass action temperaturetemperature

Hydrolysis and CondensationHydrolysis and Condensation

hydrolysis: complex organic molecules are hydrolysis: complex organic molecules are catabolized to simpler forms for assimilationcatabolized to simpler forms for assimilation

condensation: molecule of water is formed condensation: molecule of water is formed in this anabolic processin this anabolic process

Oxidation and Reduction rxnsOxidation and Reduction rxns

oxidation: transfer of either oxygen or oxidation: transfer of either oxygen or hydrogen atoms, or electronshydrogen atoms, or electrons– loss of electrons, gain of valenceloss of electrons, gain of valence– oxidizing agent is electron acceptoroxidizing agent is electron acceptor

reduction: gain of either oxygen or hydrogen reduction: gain of either oxygen or hydrogen atoms, or elctrons atoms, or elctrons – gain of electrons, loss of valencegain of electrons, loss of valence– reducing agent is electron donorreducing agent is electron donor

together are called redox reactiontogether are called redox reaction

e.g.e.g.

NAD to NADH + H or FAD to FADHNAD to NADH + H or FAD to FADH22

Energy Expenditure Energy Expenditure Measurements:Measurements:

Direct Direct – bomb calorimetrybomb calorimetry

IndirectIndirect– closed circuitclosed circuit– open circuitopen circuit

ATP, energy currency of the ATP, energy currency of the bodybody

stores small amounts, 85g or 3 ozstores small amounts, 85g or 3 oz intermediate compoundintermediate compound part of energy receiver-energy donor cyclepart of energy receiver-energy donor cycle all energy can be transformed or converted all energy can be transformed or converted

to ATP equivalentsto ATP equivalents ATP equivalent is the energy differential in ATP equivalent is the energy differential in

the conversion of ATP to ADP, and vice the conversion of ATP to ADP, and vice versaversa

Cleaving of ATPCleaving of ATP

the cleaving of ATP, hydrolysis of ATP can the cleaving of ATP, hydrolysis of ATP can occur in the presence or absence of oxygen occur in the presence or absence of oxygen is termed nonaerobicis termed nonaerobic