Training Adaptations

LIVER SKELETAL MUSCLE TISSUE Adrenal Gland Adipocytes Mitochondria

TRAINING WILL: Decrease RER Does not effect sub-max oxygen uptake Increases LT and lowers muscle and blood lactate at any sub-max workload

Aerobic training can cause % increases in mitochondrial mass per gram of skeletal muscle. However, when express per gram of mitochondrial protein training does not alter specific activity.

Total CHO: Pre = 145 umol/min Post = 100 umol/min or a 50% decrease This is due to decrease reliance on blood glucose and muscle glycogen

Training decreases R a (rate of appearance) of glucose from the liver. This means less glycogen depletion in liver.

Muscle Glycogen Depletion

With training you can double your mitochondrial mass, thus at any giving work load each mitochondrion will only be working (ie producing ATP) at half the rate it was before training. The main stimulus for increases in oxidative phosphorylation is ADP. Therefore the increase in intracellular ADP must be less in trained individuals.

 blood lactic acid Training Adaptations  # mitochondria  epi/norepi release during exercise  muscle & liver glycogen use  intramuscular fat use  # MCT’s (via  mitochondria)  CAT I (ß-oxidation)  cAMP

Training Adaptations (cont.) Two major changes that occur with training 1.)  # mitochondria in muscle cells can be doubled at most 2.)  epi/norepi release during exercise training  sympathetic activity at any given work load

Benefits of adaptations to training 1.)  Glycolysis –Spares CHO, liver glycogen –maintains blood glucose (CNS) –mechanisms:  catecholamines   PFK activity  mitochondria  faster ATP generation,  [AMP&ADP]   PFK activity 2.)  Blood Lactic Acid keeps blood pH normal mechanisms:  glycolysis  mitochondria (more MCTs)

Benefits of adaptations to training (cont.) 3.)  Fat use –  fat use from adipocytes via  epi/norepi –  fat use from intramuscular TGs –mechanisms:  mitochondria (via  in CAT I activity)  acetyl CoA production   PFK   glycolysis Take home point: *Training  glycolysis &  Fat use via  mitochondria &  catecholamines*

Muscle Glycogen vs. FFA Expenditure