Training adaptations Part 1 c Flashcards
strength training adaptations:
due to increase in muscular size: may result in a decrease in capillary density
may impair transport of energy from mitochondria to sites of energy expenditure
general interference between strength and endurance training (aerobic)
there may be competition for protien synthesis between mitochondria and contractile proteins
with too much training, you may get increased production of “stress hormones” (cortisol) which may be “catabolic” and break down protein
combining aerobic and strength training
aerobic may interfere with strength training
-added energy needed for intense endurance training may limit muscular growth
-short term bout of high intensity aerobic inhibits immediately subsequent muscular activities
-combining different modes of exercise induce antagonistic molecular level, intracellular signalling mechanisms that could negatively impact muscles adaptive response to resistance training
strength training may interfere with aerobic training
may depend on load characteristics
-muscle hypertrophy results in mitochondrial (and capillary)
-mitochondria are needed for aerobic metabolism
low reps/high load =more impairment
higher reps (8-10)/moderate load = less impairment
muscle fiber after strength training with low reps and heavy load
hypertrophy, without added mitochondria or capillaries
influence aerobic metabolism and endurance performance
for focus more toward endurance
moderate load / higher reps
fiber area increase (significant hypertrophy)
capillarization
-capillary to fiber density ration increases
-capillary density stays the same
mitochondrial
-mitochondrial number increases
-mitochondrial density stays the same
timing of training sessions might be important
doing aerobic exercise 6 hours before resistance training enhances translation, reduces myostatin and increases muscle mass more than doing resistance training alone
doing aerobic training immediately after resistance training reduces satellite cell activation compared to when resistance training is done
increases mitochondrial and capillary density (no increase in fibre size, but increase in cap and mit #)
aerobic endurance training
decreases mitochondrial and capillary density (as fiber area increases, no change in mit or cap #)
olympic weightlifting
-low reps, high intensity
has no effect on mitochondrial and capillary density (as fiber area increases, but so does cap and mit #)
body building
-moderate reps, moderate intensity
results in the greatest increase in muscle fibre size
body building
-moderate reps, moderate intensity
results in an increase in capillary to fiber ratio (increase in cap #)
body building
-moderate reps, moderate intensity
aerobic endurance training
flexibility training
training flexibility will add sarcomeres in sequence/series to increase length of muscle
vs. adding sarcomeres in parallel as seen with resistance training
no hyper trophy
increase in capillary and mitochondria (# and volume)
increase in capillary and mitochondrial density
results from…
endurance training
significant hypertrophy
increase in capillary # and mitochondria #
no change in capillary and mitochondria density
due to…
hypertrophy resistance training
hypertrophy
no increase in capillary and mitochondria (# or volume)
decrease kitochnorial and capillary density
results from…
strength resistance training
muscle adaptation with aging
muscle mass peaks at age 25-30 years
from 15 to 80 years of age, fiber number decreases by 48%
muscle fiber area does not decrease until 70 years, then decreases by 20-30%
-primarily type II
why might the tricep be preserved more with aging?
Need to push up from sitting down,
Become weaker in the lower body, lack of use. Pushing up to get out of chairs, using arms
what type of training program might you recommend for an older adult
Lower body muscle groups (there is more muscle loss in the legs, lack of use)
resitancece training in particular
higher velocity work, reaction time, jumping
resitance training exercise that goes till failure, working the type II muscle fibers
motor units and aging
which muscle group do you think had the different unit count between the runners vs. non-runners
the tibialis anterior
muscle aerobic capacity
decreases with age
due to decreased and
reversibility of age related changes
_____ and ______ can increase with training in older people up to levels that are equal to young active individuals
mitochondria and capillaries
older trained peoples maximal aerobic power may still be lower because of changes in their ability to deliver blood/oxygen to the muscles (changes in their heart and lungs)
estimating motor unit number
you can estimate the EMG amplitude of ALL motor units serving a muscle by stimulating the nerve innervating that muscle
you can also estimate EMG amplitude of individual motor units within that muscle using needle EMG
which muscle sample is from a young (20y) person and which is from an old (80 y) person. Give two reasons
Muscle fibers are larger
More fast twitch fibers
inflammation/oxidative stress
oxidative stress is increased with aging (may cause damage to proteins, DNA)
oxidative stress (release of damaging reactive oxygen species) is caused by cells that are activated during muscle damage/inflammation
oxidative stress may also be caused by mitochondrial stress
changes in oxidative stress/inflammation with training
training may increase production of anti-oxidant enzymes
training induces an increase in new mitochondria so that the ratio of old damaged mitochondria to new undamaged mitochondria changes
-this reduces the hazardous oxidative stress produced
what hormonal diff between the sexes allows males to have greater muscle mass
testosterone
who would have the greater absolute strength (who could lift more weight) males or females ?
males
if you had a male and female with the exact same amount of muscle mass, would the male be stronger
no
who has the greater absolute increase in strength (increase in poundage lifted) with training
males
who has the greater relative increase in strength (percentage change from starting. weight) with training
either the same or females
are females closer to males for upper or lower body strength
lower
sex differences in muscle strength
absolute muscular hypertrophy occurs to a much grater extent in men
on a relative basis ie. % basis change is similar across sexes
sex differences in muscle strength look at
absolute muscle strength
muscle cross sectional area
relative strength
differences in muscle strength
absolute muscle strength (total force exerted)
males score 30% higher on lower-body lifts
50% higher on upper body lifts
differences in muscle strength
-strength related to muscle cross-sectional area
-specific tension is similar in males and females most different eliminated
-regardless of sex, human skeletal muscles generates a maximum of 30 N of force/ sq. cm of muscle cross section
sex differences in muscle strength
relative muscle strength
allometric scaling
allometric scaling: mathematical/statistical process to establish a relationship between a body size variable and in this case, muscle strength
-attempts to allow muscle strength to be understood free of the effects of variables naturally relating to it
summary of sex differences in muscle strength
sex difference seems to be in muscle quantity not muscle quality
muscle quality
although there are no sex differences in potential muscles quality, that is not to say every individual has the same acquired muscle quality
muscle quality= muscle strength/muscle size
