Kin 381 - Adaptation

homeostasis

- the tendency for the human body to keep all systems at a default level

heterostasis

• idea that different parts of the body can be maintained deliberately out of sync with each other

• body desires to "normalize as quick as possible"

regular exercise

- body learns to maintain the normal function values longer in balance and restore function more quickly

adaptation

- the body learns to cope with the repeated demands through functional and morphological adaptations

aerobic training adaptations

• increased:

cardiac output blood volume hematocrit heart volume blood flow to lungs size/number of mitochondria mitochondrial enzyme activity capillarization fat oxidation enzyme activity blood supply to heart stroke volume left ventricle volume ventricular wall thickness

• Decreased:

peripheral resistance

resistance training adaptations

• increased

muscle strength muscle power balance and coordination BMR lean tissue mass muscle endurance motor performance insulin sensitivity

• Decreased:

% body fat low back pain sarcopenia and osteoporosis insulin concentration/response to glucose challenge

• increase of individual cross-section of a muscle fibre

• dependent on resistance to muscle contraction and total number of concentrations

myofibril hypertrophy

- contractile hypertrophy

sarcoplasmic hypertrophy

• non-contractile hypertrophy

• increase interfibrillar fluid, ATP, glycogen, phosphocreatine, mitochondria

fast glycolytic

• increase with training

• high contraction rates

• large force

fast oxidative-glycolytic

• increase with training

• high oxidative and glycolytic enzymes

• increased potential for powerful muscle contraction

60

Myosin makes up ____% of the total protein content of a muscle fibre with actin and tropomyosin making the next largest contributions therefore - increased myofibrillar protein

fibre type %

• aerobic exercise causes increase in more type 1 fibre (oxidative)

• same is true for any other type of activity including resistance training

true

True or False: fibre type is genetically determined

aerobic training (enzymes)

• increases activity of oxidative enzymes (citrate synthase, Krebs cycle, presence of mitochondria)

• reduction in activity of anaerobic enzymes

• increased blood volume

• increased mitochondrial and capillary density

neural adaptation

• level of the CNS and spinal level

• increase strength without increase cross-sectional area

• increased neural drive of agonist activation

• increased motor unit firing, increased motor cortex signal

• decreased antagonist activation

connective tissue adaptations

- most animal studies indicate that endurance and resistance training can increase max strength of tendons and ligaments

bone adaptations

• PA (stress/strain) causes an increase in BMD

• weight bearing / tendon stress through resistance training are indicated

• site specific

wolff's law

- the densities, and to a lesser extent, the sizes and shapes of bones are determined by the magnitude and direction of the acting forces applied to bone

first 2-6 weeks (resistance training)

• rapid increase in strength due to neural adaptations

• no difference in rate of progressions between males and females

• some cellular / mechanistic adaptations

• hypertrophy may occur faster than previously thought

10+ weeks (resistance training)

• continued strength gains mostly due to cellular adaptations

• greater hypertrophy in males due to presence of androgenic anabolic hormones (testosterone)