Exercise psy 10

winniesmith2's version from 2018-01-09 14:30

Section 1

Question Answer
Endurance trained individuals will have a high percentage of what fibre type type 1
Endurance training promotes shift from what muscle fibre to whatfrom fast-to-slow in skeletal muscle fibre types.
What is the major effect of aerobic training to convert some type llx to type lla and type 1 fibres.
Endurance training is a potent stimulus for whataltered myosin heavy chain (MHC) gene expression.
Exercise training induces what in capillaries angiogenesis, an increase in capillaries
What is the effect of angiogenesis increased surface area for diffusion. Improved rate of transfer of oxygen, nutrients and waste products.
Why growth factor is angiogenesis thought to increaseexpression of vascular endothelial growth factor (VEGF)
What effect does endurance training have on mitochondriaincrease in size and number and more fold of cristea= more surface area. Fibre type specific.

Section 2

Question Answer
What is myoglobin response to endurance training Reported increases of upto 75-80% but other studies in humans have found no change. Up to 2 fold increase in other mammals, humans less convincing. Proportionate to change in fibre type? ....therefore, no or not proven for humans.
Simplified signal transduction pathwaySignal event, turns on master switch, this causes cascade of activation - protein kinases. This causes amplification and has an effect on multiple targets; regulation of metabolic pathway, regulation of gene expression, regulation of protein synthesis.
Examples of signal events change in length and tension of muscle, change in calcium concentration. change in ratio of ATP to AMP (signifies energy available). Changes in redox potential, for example changes in NADH levels for electron transport change.
What does AMPK mean Activation via protein kinases
What does AMPK doVarious different roles within the muscle cell has an influence of the rates of glycolysis, rate of fatty acid oxidation, rates of transportation of glucose into muscle cell, activates other signally proteins- knock on effect.
What is mitochondrial biogenesis regulated bythe up regulation of PGC-1a
What is PGC-1aa co-activator responsible for increase in mitochondrial proteins.
What is the mitochondrial biogenesis signal transduction pathway Signal (decrease in glycogen or increase in the AMP/ATP ratio). This causes activation via protein kinases. This causes increased expression of PGC-1a, this causes up regulation of mitochondrial genes, mitochondrial biogenesis and the decrease of glycolysis, increases fatty acid oxidation and lipolysis. and up regulation of GLUT4 transporters. Aim to save depletion of muscle glycogen stores.
If with endurance we can increases the expression of PGC-1a and the expression of GLUT4 transporters, what does this suggest that we can increase muscle glycogen stores in the muscle.
What are GLUT4 transportersproteins that aid transportation of glucose into cells
Compare muscle glycogen in untrained and trained adults Trained athletes had an increased amount of muscle glycogen (370 to 580 mmoll/kg/dw) and after exercise to the depletion of glycogen stores, trained athletes had a higher glycogen concentration at 15mins, 6h and 48h. Shows support for increase presence GLUT4 transporters transporting glucose into the muscle more readily.

Section 3

Question Answer
Insulin sensitivity; Houmard study.Ppts; Overweight males with BMI between 25-35 Kg.m-2. Had 4 groups, one control, one low volume mod intensity. one low volume high intensity, and one high volume high intensity. Results found that the relative change for insulin sensitivity was highest at 88 for low/med group who did longest time of exercise at 171 mins, followed by 83 for high/high group who did 167 mins, and 38 for low/high group who did 114 mins a wk, suggesting it is the duration of exercise which influence adaptations for glucose uptake into cells (GLUT4 transporters the most.)
describe change in GLUT 4 expression after exercisein humans GLUT4 mrna expression is significantly elevated immediately after a single bout of exercise. and remains elevated for several hours after exercise. but returns to pre exercise levels within 24hrs. That suggest that training induced responses from repeated transient increases in GLUT4 transcription. Build up of glut4 proteins by increased glut4 mrna expression.
What effects GLUT4 movementin response to exercise of in response to insulin, GLUT4 transporters are translocated to the edge of the cells.
What does glycogen synthase do and is it effected by endurance training Is the enzyme that helps make glycogen from glucose, evidence that endurance training causes an increased presence of glycogen synthase.
So do we get changes in our stores of intercellular glycogenyes. More glucose delivered in and more glycogen synthase to build it into glycogen

Section 4

Question Answer
Fat oxidation; how does fat move from adipose tissue into the muscleAdipose tissue is comprised of triglycerides (3 fatty acids and 1 molecules of glycerol) which are converted to FFA and the glycerol. The FFA then move into the blood stream by albumin. VLDL then moves FFA into the muscle, which then go into the mitochondria to be oxidised by beta fat oxidation, then the krebs cycle and then the electron transport chain= high yield of ATP.
Where is fat stored in adipose tissue stores and in intermuscular triglycerides
What are intermuscular triglycerides stores of fat within the muscles themselves. Potentially more readily available for oxidation during exercise. Broken down on site by the mitochondria.
What happen to glycerol goes to the liver and undergoes gluconeogenesis. forms new molecule of glucose.
Morgan et al; Intramuscular triaglycerol IMTAG10 males, unilateral leg extension. After exercise bilateral biopsies of both legs (act as before and after). Found a 2 fold increase in the IMTAG following exercise training. Caution; large variability of findings. Possible contamination from adipose tissue on way through to muscle.
what are Intramyocellular lipids closely associated to the muscle cell, not within but just outside it.
Study for intramyocellular lipids 9 untrained males, standardised diet. Alternating endurance and interval training. After training; signif higher levels and more used within exercise. Endurance causes increase.

Section 5

Question Answer
Oxidative enzyme activity - importance may have increased glucose and ffa, but Need to increase capability of breaking them down.
Oxidative enzyme activity changes with exercise over 7 months of training. SDH activity = more krebs cycle activity. Over training, sustained more daily exercise. and over 800% increase of SDH enzyme, and increase in V02 max. VO2 max increases and then plateus, increase may be due to increase in SDH but SDH keeps increasing even after vo2 plateuos suggesting that it is important for some other factor - altering substrate utilisation, more time to exhaustion.
Oxidative enzyme activity; cross sectional studies; leg muscle enzyme activities. in untrained individuals, levels of SDH and CS is lower than those trained, could effect oxidative capacity, such as vo2 max and alterations in fuel utilisation.
What does SDH stand for succinate dehydrogenase. Oxidises succinate to fumerate (FAD reduced to FADH2) in krebs cycle.
What is CS catalyses the condensation reaction forming citrate (marker of intact mitochondria)
McPhee. Reponse the same for everyone? enzyme changes10 week program. increase in all regulatory enzymes. Some people either responded or didn't. Those who increased in one increased in all.

Section 6

Question Answer
Fat Oxidation can alter following endurance training; key adaptationEndurance training can markedly increase fat oxidation during submax exercise. Key adaptation to consider is the increase in mitochondrial proteins; increased activities of the krebs cycle and electron transport chain. If we are more efficient at breaking down fats we can do it more quickly, can exercise at higher intensities, fueled by fat oxidation.
Fat oxidation; freidlander, 8 untrained women before and after training programRER decreased significantly at the same relative intensity. Increased contribution of fat oxidation. and at higher intensities.
Why does fat oxidation increase? Bruce found that post training mitochondria FA oxidation was higher post exercise. and so was CPT-1 activity (breaks down FFA).
Cross over between fat oxidation and carbohydrate oxidation Theres a point where in exercise intensities increase, carbohydrate oxidation takes over from fat. with training this can be shifted to the right and fat oxidation still occurs at higher concentrations.