Chronic adaptations

1. ^ stroke volume
2. Resting and sub-max HR decrease
   1. Bradycardia; when HR < 60

1. Q can increase at maximal exercise though

1. More capillaries
2. Slow twitch muscles have greatest increase
3. +ve relationship between # of (mitochondria and capillaries)/fibre
4. +ve relationship between # of capillaries/fibre and muscle fibre diameter

1. Less blood sent to active muscles at except max intensity
   1. More blood sent to skin
      1. Better thermoregulation
   2. More blood is sent to muscles with higher % of type 1 fibres

1. ^ plasma (within days)
   1. Factor in thermoregulation ^
   2. Factor in SV ^
2. ^ in RBC count (haematocrit)

1. Increased lack of lactate removal
2. Decreased rate of lactate production
   1. Basically delays fatigue

1. ^ pulmonary diffusion

1. Ventilation decreases above rest

1. Little to no change in strength or power
2. Aerobic system contributes more ATP
3. Muscle structure
   1. Type 1 (slow)
      1. ^ oxidative capacity
      2. Fibres increase in size
   2. Type 2 (fast)
      1. Take on characteristics of type 1
         1. Do not become type 1
4. a-VO2-diff gets more efficient
   1. Major contributor to VO2max ^
5. ^ Myoglobin
   1. Compound that transports O2 to mitochondria
      1. Haemoglobin but inside the muscle
      2. Ability to transport increases
6. Mitochondria
   1. Site of aerobic respiration
      1. Resynthesises ATP
   2. ^ Oxidative enzymes
      1. Related to ^ %VO2max before LIP
   3. ^ size and number
      1. ^ aerobic ATP resynthesis
   4. Ability to oxidise fats ^
      1. Specifically FFA
      2. Glycogen sparing ^
   5. Ability to aerobically utilise glycogen ^
      1. Glycolysis

1. NO change in SV

1. ATP
2. Glycogen
3. PC

Nota:

• Ability to respire without oxygen during anaerobic metabolism

1. Improved neuromuscular pathways
   1. More efficient and forceful contractions
2. ^ motor unit recruitment
3. ^ motor unit firing frequency
4. ^ recruitment of fast twitch fibres
5. ^ motor unit co-ordination
6. ^ co-contraction (agonist/antagonist)
7. Increased activation of stabilising muscles
8. Tend to occur within first few weeks of training

1. ^ # and size of myofibrils
   1. Muscles built with chains of these
   2. ^ contractile proteins
      1. Actin and myosin
   3. No increase in # of muscle fibres, only size