______ factors: adaptations within NS accounts for the rapid strength increases without increase in muscle size early in resistance training.
Describe the 5 neural factors that improve strength and hypertrophy?
1. greater efficiency in neural recruitment patterns
2. increased central nervous system activation (cortical drive and alpha motor excitability)
3. increased motor unit recruitment and firing rate
4. improved motor unit synchronization
5. lowering of neural inhibition
True or false: increased tendon stiffness transmits muscle force more powerfully.
True or false: a muscle with more proteins produces no more force than those with less.
True or false: resistance training thickens and strengthens connective tissue.
True or false: muscle fiber type is likely fixed before birth.
True or false: fibers convert from type II to type I.
transformations occur withing particular fiber types. The most common is the following?
type IIb-->Type IIa
In resistance training, which type of fibers get bigger? FT or ST
Is there an increase in the number of muscle fibers with RT in animals? in humans?
no clear evidence
_% loss in muscle mass per year after the age of 35.
_-_% decline in muscle mass per year after age of 60.
In sarcopenia, muscle fiber changes with aging:
1.______ muscle fiber size
2.______ number of muscle fibers
decreased muscle fiber size (atrophy)
decreased number of muscle fibers
Studies have shown that with aging, (Type I or Type II) fibers are affected the most.
Muscle fibers change with age. It is thought that there is a selective loss of (Type I or Type II) fibers. To make up for the loss, (Type I or Type II) fibers take over, or acquire reach out and innervate the muscle fibers.
Name the three factors that play a role in Sarcopenia.
1. hormonal changes
2. muscle contains at least 5 different myosin heavy chain isoforms
3. Older muscles may express multiple myosin heavy chain isoforms in the same fiber (blurring of type I and type II fibers)
Strength increases up to age__?
Plateaus from ages _-_?
declines 15% per decade between __-__?
The most precipitous loss of strength occurs after the age of __?
Generally about 30% loss per decade after this age.
_____: maximum rate of work performance
force x velocity
With age, which decreases more quickly, power or strength?
strength, generally 1-2% per year after 60
power, generally 3.5% per year
Aerobic capacity decreases _% per year from age 25.
True or false: the rate of decline is not dependent on the physical activity of people?
false (rate of decline can be reduced to .25 ml/kg/min per year)
Older muscle is unabel to utilize oxygen the way younger muscle can. Why
reduced oxygen extraction
reduced cardiac output
______: age associated decline in muscle mass
3 age related factors that affect sarcopenia?
2 behavioral factors that affect the rate of sarcopenia?
what factors are responsible for decreased strength in older men and women?
1. changes in force producing capability of muscle tissue
2. changes in neural activation of muscles
Disability pathway model:
_____: abnormality occuring at the level of cell or tissue.
_____: abnormality occuring in specific organ or organ system.
____: limitation in performing fundamental tasks at whole body level.
____: limitations in performing socially defined role within social or physical environment.
Word bank: disability, functional limitations, impairment, pathology
Do we maintain muscle mass and size with age?
Does resistance training in older adults improve functional performance?
Describe the concept of the functional threshold?
There is a threshold of strength, at which, and increase beyond thereof will not yield changes in functional status, and dropping below will result in a decrease in functional status.
Describe that 5 factors that leads to declined function in pulmonary function.
1. decline in elastiity of bony thorax
2. decrease in elastic recoil of lungs
3. weakening and loss of muscles involved in respiration
4. decrease in alveolar surface area
5. decrease in CNS responsiveness
True or False: aerobic exercise can increase pulmonary vascularization and strengthen respiratory muscles?
true (most other changes to pulmonary function are irreversible)
Cardiac output decreases steadily with aging (due to decreased hr and sv and reduced sympathetic input). How do highly trained athletes account for these changes. (Increased or Decreased) cardiac filling. (Increased or decreased) SV through frank starling mechanism.
increased cardiac filling
increased stroke volume
Are there differences in gender with aerobic trainability in the elderly?
if so, what differences occur?
Men: 2/3 of VO2max increase due to SV and 1/3 due to a-v o2 difference.
Women: 100% of VO2max increase due to O2 difference
Aerobic capacity changes in women may be due to "peripheral" changes and not cardiovascular changes. lack of stroke volume changes due to:
1. blunting of normal increase in plasma volume
2. depression of cardiopulmonary baroreflex sensitivity
3. estrogen-deficiency-related decreases in vascular compliance
After the age of ___, there is a progressive increase in body fat throughout life.
90% of peak bone mass achieved by age __. (peak by age __)
Bone mass decreases 1-2% per year after age ___?
Osteoporosis contributes to ___ of hip fractures.
7 Factors that affect Bone mass:
4. hormonal factors
6. weight bearing exercise
7. lifestyle factors
Most important factor contributing to mortality is what?
low fitness level
3 things or activities that may lead to muscle soreness?
1. unaccustomed novel physical activity
2. unnaccustomed increases in activity
3. activities that emphasize eccentric contractions
How do eccentric contractions damage the muscle?
1. increased strain on myofibrils (overstretched sarcomere theory)
Describe some of the characteristics of Delayed Onset Muscle Soreness (DOMS)? i don't care how many, just get an idea. some of them are vague and stupid.
: appears 6 hours after exercise
: peak 24-48 hours after exercise
: resolved by 5-7 days
: dull aching pain
: distal 1/3 of muscle, MT junction
: Pain evident upon movement
Theory on DOMS: _____ ______ _____: produced during high intensity exercise and is quickly carried away from the muscle.
Lactic Acid Theory
Theory on DOMS: _____ ______ _____: increased hypoxyproline at 48 hours post-exercise. Pain reported at distal 1/3 of muscle. Muscle more compliant than CT.
Connective Tissue Theory
Theory on DOMS: _____ _____: Type IV nerve endings sensitive to 38-48 d C. Higher local temperatures generated during eccentric exercise. Rhabdomyolysis exacerbated by hyperthermia.
Theory on DOMS: _____: injury to muscle membrane leads to the release of Ca2+ in the cell membrane with the production of arachidonic acid and a big cycle that i don't really understand but you can look at if you like. End result is swelling and pain.
Short term effects of DOMS on performance:
- _____ in strength
- _____ in range of motion
-_____ of motor control
reduction in strength
reduction in range of motion
loss of motor control
_______: "muscle loosening" Severe breakdown of skeletal muscle tissue. Characterized by muscular pain, severe weakness, strength loss, swelling, stiffness, and increased muscle protein Creatine kinase, myoglobin. (dark urine)
Rhabdomyolysis leads to myoglobinuria and then to ____ ____ ____? What is the treatement for this?
acute renal failure (aggressive fluid replacement is the treatement)
Rhabdomyolysis can lead to compartment syndrome which can lead to ___ ____ ____? What is the treatment?
loss of function (fasciotomy is the treatment)
Rhabdomyolysis can lead to hyperkalemia and then to ________. What is the treatement?
life threatening dysrhthmias (calcium chloride, glucose, and insulin to address the hypercalemia/vasoconstriction)
Heat increases __x during exercise?
Heat is dissipated 4 ways:
conduction, convection, radiation, evaporation
(thermal injury occurs when these are compromised)
How does the body respond to hot environment?
-vasodilation decreases blood pressure
-change in BP results in peripheral vasoconstriction, increases core temp, and reduces heat loss
-heat dissipation is compromised by thermoregulatory mechanisms and environment
Percentage of obese has (doubled, tripled, or quadrupled) in the past 20 years.
Why has the prevalence of obesity increased?
-availability of inexpensive and highly palatable foods (soft drinks)
- proportion of or total calories from fat
- portion sizes
- eating out more often (fast foods)
- sedentary lifesytles
2 things happen when we gain weight. What are they?
1. increase the size of fat cells (hypertrophy)
2. increase the number of our adipocytes (hyperplasia)
The major cellular difference in adipose tissue mass between obese and non-obes is total adipose cell _____?
True or false: with weight loss, major change in adipose cellularity is shrinkage of the adipocyte with no change in adipocyte number.
4 problems with low CHO diets?
1. high intake of saturated fat
2. low intake of vegetables, fruits, and fiber
3. exercise tolerance is reduced
4. greater lean tissue loss
Is there a genetic component to weight loss/gain?
What is the most successful plan when it comes to weight loss?