Training Adaptations Part 1 structural and functional adaptions to training Flashcards
factors that modify human strength
PA
muscle mass
genetics
nutritional status
endocrine influences
nervous system activation
environmental factors
skeletal muscle adaptation
- nucleus of muscle fibers (cells) contain deoxyribonucleic acid (DNA)
- DNA contains genetic material that encodes the proteins that are to be made in the cell
-many changes (adaptations) that occur within the muscle occurs at the level of the genes
-ribonucleic acid is a molecule that transcribes (copies) a portion of DNA and takes it out of the nucleus for protein synthesis
transcription
mRNA copies a message from DNA
translation
amino acids match up with mRNA
muscle cell modelling
exercise activates a gene sequence on DNA
mRNA copies a message from DNA
transcription
mRNA leaves the nucleus
amino acids match up with RNA
translation
a protein is degraded
genotype
describes your type of genes
phenotype
describes the outward appearance of muscle
(usually reflect genotype)
protein degradation see slide
overview (how translation, transcription)
genes activated, in turn activate transcription and translation of messenger RNA and stimulate protein synthesis
- particularly the protein filaments (if talking about muscle)
protein degradation overview
protein synthesis
myofibrils (actin and myosin )
thicken and increase in sarcomere #
responses of satellite cells to resistance training
proliferation
differentiation
multiplication from one to many cells=proliferation
development of a cell = differentiation
both will occur to satellite cells with resistance training
resistance training
_______ the number of satellite cells and myonuclei
increases
resistance training
Satellite cells are incorporated into the muscle fiber as ______
new myonuclei
resistance training
new myonuclei results in increased __________
protein synthesis
responders vs non-responders to resistance training
people who has great number of satellite before a resistance training program had greater muscle hypertrophy after the program
myogenic regulatory factors
MRFs
these are proteins known as “transcription” factors
they turn on transcription
they are involved with satellite cell activation
they are increased with resistance training
myostatin
a protein that halts satellite cell activation
absence of myostatin
increase protein
larger and stronger
myostatin is found to _____- with resistance training
decrease
therapeutic use of myostatin
potential use for diseases characterized by significant muscle wasting
- review of studies on myostatin blocking suggest research still very much in development stages
supplements
buyer beware
-creatine monohydrate
-leucine
-glutamate
protein turnover
-cycle of synthesis and degradation
-types of proteins important for exercise
protein turnover
types of proteins important for exercise
contractile proteins
regulatory Proteins
mitochondrial proteins
enzymes
true or false
mRNA translates info from DNA to combine with amino acids through the process of transcription
false
true or false
satellite cells increase in response to resistance response to resistance training and become myonuclei
true
true or false
an abundance of myostatin allows for excessive muscle growth
false
what specialized cells are activated with exercise training to increase the number of nuclei in muscle fibers?
satellite cells
what types of protein can these new nuclei produce in response to
endurance training
mitochondrial protein, oxidative enzymes
what types of protein can these new nuclei produce in response to
strength training
muscular adaptations with aerobic endurance training
increases in mitochondrial protein
mitochondrial protein = oxidative enzymes
enzymes in the mitochondria
carbohydrates, fats, proteins, = lots of energy (ATP)
oxidative enzymes: slow but efficient
oxygen transport improves
increase in capillarization
increased capillary density
= # of capillaries/fiber area
capillaries: deliver blood which contains oxygen
hemoglobin: oxygen carrier in the blood
Myoglobin: oxygen carrier in the muscle
oxygen transport improves
increase # of mitochondria
increase mitochondrial density
site of oxygen utilization in the muscle
effects of increased capillarization
as capillaries increase in number, the velocity of blood flowing past the muscle decreases
this allows a grater diffusion of oxygen from hemoglobin in blood to the muscle cell
in the muscle cell (fiber) oxygen is carried by myoglobin to the mitochondria
in the mitochondria, oxygen is used to breakdown fats, carbohydrates and proteins for fuel
increased oxygen utilization
more oxygen to muscles= more ATP from aerobic metabolism
max VO2= indicator of aerobic fitness
- the more O2 utilized the greater level fitness
factors that modify the expression of human strength
neural factors include:
more efficient neural recruitment patterns
increased CNS activation
improved motor unit coordination
lowered neural inhibitory reflexes
inhibition of GTO
neural accounts for most initial strength gains
factors modifying strength overview
muscular changes include increases in
- muscle size = hypertrophy
-enzymes phosphofructokinase (PFK), creatine and myokinase
-resting levels of ATP and phosphocreatine
-strength of tendons and ligaments
-bone mineral content
factors modifying strength overview
muscular changes include decreases in
% body fat
mitochondria density
what is the difference between hyperplasia and hypertrophy
Hyperplasia = more cells
hypertrophy= larger muscle cells
which one is more likely to occur with resistance training with regards to skeletal muscle fibers
increase in size (hypertrophy)
which skeletal muscle fibers are most likely to respond to resistance training with an increase in size
Type II are most likely
You will get it in both, but type II have increased potential for hypertrophy
adaptations to resiatcne training
hyperplasia: an increase in the number of cells (muscle fibers)
hypertrophy: an increase in the size of cells (muscle fibers
hypertrophy is more likely to occur with resistance training
evidence of hyperplasia
some in animal studies (cats, birds)
humans studies
- autopsies
CSA of individual fibers of body builders
anabolic steroids
genetics
estimated muscle fiber number
study of bodybuilder vs. non-bodybuilder
-no difference in estimated muscle fiber number
-larger muscles in body builders was due to larger muscle fibers (hypertrophy)
estimated muscle fiber number
-estimation of muscle fiber number before and after a few months of resistance training
-no change in estimated fiber number
there was a significant increase in muscles fiber size (hypertrophy)
adaptations to resistance training (continued)
both ______ show hypertrophy with strength training
________ have greater potential for hypertrophy than _________
muscle fiber hypertrophy (increase in size)
type I and type II fibers
type II type I
adaptations to restiance training programs
see slide
fiber type shifting in resistance training
type IIX to type IIa
no shift between type 1 and type 2 (from training)
why is there a shift to a “slower” type (resistance training)
this may allow more economical cross bridge cycling
cross-bridges cycle at a slower rate to allow increase force of contraction
remember force velocity curve
shift with training
fast glycolytic (Iix) to Fast oxidative glycolytic (IIa)
FG
- less mitochondria
-less capillaries
-less myoglobin
FOG
- more mitochondria
-more capillaries
-more myoglobin
