Aerobic Exercise Set 1
Nueromuscular adaptations to exercise
- neural adaptations due to : changes occurring in activation of motor units. Improved recruitment patterns, improved neural drive. Maybe a reduction of the sensitivity of the golgi tendon organs, to allow for greater force production. Exercise training may also lead to increased # of vesicles that store acetychloline to allow for greater amount of neurotransmitter secretion at the neuromuscular junction and allow for greater for production. There are also nuero-endocrine changes, increase bone density,
Endurance is:
-ability to perform work for prolonged periods of time -ability to resist fatigue -cardiovascular endurance -muscular endurance
Characteristics of the anaerobic glycolytic system?
-no oxygen required -outside mitochondria---quickly available -intermediate maximal power (400 meter dash) -limited capacity- poor efficiency
Fitness: ability to perform physical work and involves the following factors: (4)
1. cardiorespiratory functioning 2. muscular strength and endurance 3. Musculoskeletal flexibility 4. body composition
What are the 3 major energy systems?
1. phosphagan or ATP-PC system 2. anerobic glycolytic system 3. aerobic oxidative system (aerobic glycolysis, krebs cycle, ETC)
How many moles of ATP from 1 mole of glucose?
2
The phosphagan system is the major source of energy for first _____ seconds of activity
20
Efficiency anaerobic ____% (+____% heat)
27, 73
aerobic system is a major source of energy after the ____ minute of exercise
2nd
In the aerobic system you get _____ moles of ATP per 1 mole of glucose
36
Efficiency aerobic ____% (+____% heat)
44, 56
-1 liter oxygen =
5 kcals
Normal pH
7.34-7.36 slightly alkaline
ATP=
ADP+P+energy=ATP
Does not depend on a long series of chemical reactions, does not depend on transporting the oxygen we breathe to the working muscles
ATP-PC system both ATP and PC are stored directly within the contractile mechanisms of the muscle
Which system uses glucose and turns it into lactic acid +energy?
Anaerobic glycolytic system
high glycolytic capacity fast contractile response recruited for power activities
Fast twitch fibers (Type 2b)
Describe normal responses to acute aerobic exercise.
Heart rate (HR) -increases Stroke volume (SV)-increases Cardiac output (Q) -increases Blood pressure (BP)-increases Blood flow -increases Lungs Dialate
Respiratory adaptations from Aerobic Training:
Increased maximal exercise ventilation, increased maximal oxygen consumption, increased tidal volume, increased extraction of oxygen, onset of blood lactate accumulation occurs at high percentage of the trained person's aerobic capacity (55% untrained vs. up to 90% trained) as a result of an increased ability to generate a high lactate level after training.
Specific adaptations from Aerobic Training:
Increased myoglobin content Increased oxidation of carbohydrates (glycogen) -increased capacity for muscle to generate energy. Increased oxygen consumption (VO2) and oxygen extraction (a-vO2 difference) Increased biochemical changes in Type 1 and Type II muscle fibers. Increased heart size and efficiency
Phosphagan system
P=C ----- P+C+energy ----goes to----energy+ADP+P =ATP
high oxidative slow contractile response recruited from low intensity exercise
Slow twitch fibers (type1)
type of activity best suited for long duration , slower rate of energy generation
TYPE 1
Which system performs aerobic glycolysis- involves the kreb cycle, and electron transport system?
The aerobic system
Aerobic System
The aerobic system is dependent on oxygen. The metabolic reactions that take place in the presence of oxygen are responsible for most of the cellular energy produced by the body. It is the slowest way to resynthesize ATP. The aerobic system—which includes the Krebs cycle (also called the citric acid cycle or TCA cycle) and the electron transport chain—uses blood glucose, glycogen and fat as fuels to resynthesize ATP in the mitochondria of muscle cells. Aerobic system is also called mitochondrial respiration.
Glycolysis System
This system is mainly used for all-out exercise lasting from 30 seconds to 2 minutes. It is the second fastest way to resynthesize ATP. During glycolysis, carbs in the form of either blood glucose (sugar) or muscle glycogen (the stored form of glucose) is broken down through a series of chemical reactions to form pyruvate (glycogen is first broken down into glucose through a process called glycogenolysis) For every molecule of glucose broken down to pyrucate through glycolysis, two molecules of usable ATP are produced. Thus, very little energy is produced through this pathway, but you get energy quickly. Once pyruvate is formed, it has two fates: conversion to lactate or conversion to a metabolic intermediary molecule called acetyl coenzyme A (acetyl-CoA), which enters the mitochondria for oxidation and the production of more ATP (Robergs & Roberts 1997). Conversion to lactate occurs when the demand for oxygen is greater than the supply (i.e., during anaerobic exercise). Conversely, when there is enough oxygen available to meet the muscles' needs (i.e., during aerobic exercise), pyruvate (via acetyl-CoA) enters the mitochondria and goes through aerobic metabolism.
True or false: Enzyme systems function only in limited temp range
True
moderate enzymes moderate anaerobic enzymes intermediate capillary density intermediate resistance to fatigue intermediate maximal contractile velocity diameter : medium twitch rate: fast max shortening velocity: fast
Type 2a
short duration, faster rate of energy generation
Type 2b
white (decreased myoglobin) low enzymes high anaerobic enzymes low capillary density low resistance to fatigue low maximal contractile velocity diameter : large twitch rate: fast max shortening velocity: fast
Type 2b
Fick equation:
VO2max = Qmax x (a-v O2max diff) maximal cardiac output (Q) and maximal arterial oxygen content; the "peripheral" part is the extraction of oxygen from the blood (a-v O2 diff).
Genetic factors and training regulate the various physiological factors that contribute to the body's ability to transport oxygen and which include:
a) pulmonary ventilation, b) diffusion of oxygen from the alveoli to blood, c) cardiac performance, d) redistribution of blood to working skeletal muscle, and e) extraction and utilization of oxygen by working skeletal muscle.
only uses carbohydrates (glycogen and glucose)
anaerobic glycolysis
What is a major source of energy from 30th - 90th second of exercise?
anaerobic glycolytic system
Measurement of energy expenditure direct calorimetry
caloric expenditure measure heat production and energy expenditure
Factors relating to rate and duration of energy production
concentration of enzymes/ substrate - capacity of the system -temperature - potential energy -----kinetic energy and heat
Energy/energy systems
energy is the capacity for performing work
A heart rate telemetry to estimate caloric expenditure
estimate oxygen with age and body weight, ok for clinical use but not an accurate measurement
mixed characteristics recruited for both anaerobic and aerobic activities
fast twitch fibers (Type 2a)
Increase heat --------
increase demand circulatory system (limiting factor)-------energy production stops
Cardiovasular adaptations to exercise
increased cardiac output due to an enhanced or improved stroke volume. Increase in heart weight/volume occurs primarily with aerobic training. Cardiac Hypertrophy is characterized by an increase in the size of the left ventricular cavity and a thickening of the myocardium. Increase in cardiac output : stroke volume increases, greater % of the ventricular volume that is pumped out with each beat., Max heart rate may increase or may decrease with exercise training , decreased heart rate at any given submaximal intensity. Increased capillarization in tissue after training, increased plasma volume and total hemoglobin after training.
anaerobic system produces ____________
lactic acid
Factors related to lactate threshold
low tissue O2 reliance on glycolysis activation of fast twitch muscle fibers reduced lactate removal
2 ways to rate fitness level
maximal exercise testing submaximal exercise testing
Open-circuit spirometry
measures vol, O2, and CO2 content of expired air -computation of oxygen consumed -accurate estimate of energy expened
pH < 6.9 or >7.8
metabolic processes inoperable
What is an energy system?
metabolic system involving a series of biochemical reactions resulting in the formation of ATP
Qualities of the phosphagan system:
no oxygen required outside mitochondria-immediately available maximal power, ie shotput maximal capacity very small
Fat as an energy substate is?
oxidation
Indirect calorimetry
oxygen utilization -energy expenditure
1 kilogram calorie=
quantity of energy to heat 1 kg of water 1 deg c
Increased aerobic capacity--------
rely more on aerobic energy production------more efficiency-------increase work capacity
Characteristics of the aerobic system?
requires oxygen to remove hydrogen ions KC-ETS inside the mitochondria Great maximal capacity small maxiimal power
specificity of training
specific systems respond to specific training stimuli, demand/stress of a specific system---adaptation
An estimation of energy expenditure from an estimation from workload is a
stress test, based on averages, mets/min
main function of the phosphagan system:
to supply energy until other systems are activated
red high enzymes low anaerobic enzymes high capillary density high resistance to fatigue slow maximal contractile velocity diameter : small twitch rate: slow max shortening velocity:slow
type 1
3 types of the skeletal muscle fiber types
type1 type2b type2a
Calorie is
unit of measurement of energy
Aerobic metabolism
used during low intensity long duration exercise. Usesd the most ATP and requires several series of complex chemical reactions.
Phosphagen System
used during short intense activities when there is a need for a large amount of power and high demand of ATP. It is the fasted way to resynthesize ATP. Creatine phosphate is stored in skeletal muscles, donates a phosphate to ADP to produce ATP. No carbs or fat are used in this process. The regeneration of ATP comes soley from stored CP. The process is anaerobic (doesn't need oxygen). It is used for all out exercise lasting up to 10 seconds
