chapter 8 exercise science

ATP

a high energy molecule that serves as the main form of energy in the human body; known as the energy currency of the body

bioenginerics

the study of energy in the human body

metabolism

all of the chemical reactions that occur in the body to maintain itself

exercise metabolism

the examination of bioenergetics as it relates to the unique physiologic changes and demnds placed on the body during exercise

first law of thermodynamics

energy cannot be created or destroyed but merely converted from one form to another 

macronutrients 

food substances required in large amounts to supply energy and include protein, carbs, and fats

substrates

intermediate forms of nutrients used in metabolic reactions to create adenosine triphosphate

glucose

the simiplest form of carb used by the body for energy

glycogen

glucose that is deposited and stored in bodily tissues, such as the liver and muscle cells; the storage form of carb

VT1

the point at which the body uses an equal mix of carbs and fats as fuel sources

VT2

the point where glucose provides neraly all of the energy for the activity

fats 

help the body use some vitamins and keep the skin healthy. they serve as energy stores for the body, in food there are two types saturanted and unsaturated 

triglyceride

the chemical or substrate form in which most fats exists in food as well as in the body

free fatty acids

the by-product of the breakdown of stored or consumed fats, metabolized exclusivly via the aerobic pathway, which uses oxygen to create ATP.

protein

amino acids linked by peptide bonds; the building blocks of body tissues

essential amino acids

amino acid that must be obtained though the diet as the body does not make it; there are NINE of these

nonessential amino acids

amino acids that can be synthesized by the body and do not need to be obtained in the diet; ELEVEN of these

negative energy balance 

when calorie intake is lower than the number of calories expended 

gluconeogenesis

the formation of glucose from noncarbohydrate sources(proteints and fats) 

ketogenesis

the formation of ketone bodies from nonfat sources, such as certain amino acids,

ketone bodies

water-soluable molecules produced in the liver as a result of fatty acid oxidation. they can be oxidized in the mitochondira to produce ATP

ketosis

a state of carb depletion where the liver manufactures ketone bodies to meet energy demands that free fatty acid oxidation cannot support

exogenous ketones

isolated ketone bodies usually consumed in supplement form

insulin resistance

the inhabililty of cells to respond to insulin; type II diabetes

ketoacidosis 

metabolic acidosis induced by vwey high levels of ketone bodies such as seen in type I diabetes or serve insulin resistance 

ADP, adenosine diphosphate

a high-energy compound occurring in all cells from which ATP is formed.

phosphorylation

the addition of a phosphate group to a molecule, such as in the transfer of a phosphate group to adenosine diphosphate to create adenosine triphosphate

anaerobic

processes relating to the absence of oxygen

glycolysis 

metabolic process that occurs in the cytosol of a cell that converts glucose into pyruvate and ATP. Anaerobic glycolysis refers to when this process occurs in the absence of oxygen

oxidative phosphorylation

a series of reactions inside the mitochondria that uses oxygen to produce ATP

aerobic

processes relating to oxygen

deamination

the breakdown of amino acids into substrates that can be used for energy metabolism

mitochondria

the parts of the cells that use nutrients to create energy for the cell; commonly known as the powerhouse of the cell

electron transport chain

a series of protein complexes that transfer protons and electrons received from the critic acid cycle through a series of reactions to create ATP

acetyl coenzyme A

producedby the breakdown of carbs through glycolysis and by the fatty acids through beta-oxidation and is the precursor for these substrates to the citric acid cycle 

beta-oxidation 

the first step in the process to break down fats via oxidative phosphorylation 

steady-state aerobic exercise

the exercise that remains at a constant intensity, with stable HR and oxygen consumption

excess post-exercise oxygen consumption (EPOC)

the state at which the bodys metabolism is elevated after exercise

atp-pc fuel substrate

phosphocreatine

atp-pc intensity supported

high

atp-pc onset of maximum atp production

1 second `

atp-pc time of exhuastion of the system 

10-15 sec

atp-pc limiting factors 

depletion of atp-pc stores 

glycolysis fuel substrate

stored glycogen and or blood glucose

glycolysis intensity supported

moderate to high

glycolysis onset of maximal ATP production

5-10 sec

glycolysis time of exhaustion of the system

30-60 sec

glycolysis limiting factors 

lactate and CO2 accumulation 

oxidative fuel substrate

pyruvate and free fatty acids

oxidative intensity supported

low to moderate

oxidative onsent of maximal atp production

2-3 minutes

oxidative time of exhuastion of the system

theoretically unlimted

oxidative limiting factors

insufficient oxygen, heat accumulation, muscle fatigue

total daily energy expenditure (TDEE)

the total amount of energy expended in one day

kilocalorie 

one food calorie. also the amount of energy needed to raise one kilogram of water by one degree C

resting metabolic rate

the rate at which the body expends energy when fasted and at complete rest

exercise activity thermogenesis

the calories expended through structured exercise or training

thermic effect of food

the energy required to digest, absorb, and process nutrients that are consumed

nonexercise activy thermogenesis

energy expenditure through daily activity outside of sturctured exercise such as walking or chores

physical activity level

the number of calories a person expends through physical activity an structured exercise

metabolic equivalent 

a measurement used to describe the energy cost of physical activity as multiple of resting metabolic rate.

energy per gram of protein

4 calories

energy per gram of carbohydrates

4 calories

energy per gram of lipids 

9 calories 

energy per gram of alcohol

7 calories

sedentary

athletes

0.8 g/kg of body weight

1.2-2.0g/kg of body weight

AMDR for protein

10-35% of total calories

ATP-PC is also known as

the phosphagen or the phosphocreatine system

is ATP-PC aerobic or anaerobic

anaerobic

ATP-PC exercise intensity 

primary high intensity 

ATP-PC time frame

10-15 seconds