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)