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Flashcards in Carbs + Exercise Deck (17):

what do carbs before exercise do and during

before- replenish muscle, liver glycogen stores

during- maintain blood glucose for glucose ox.


role of muscle glycogen/ how much we store/ exercise intensity usage

readily available for working muscle

@ low- most energy derived from ox phosphorylation

@ high- oxidation of carbs fat can’t keep up, muscle glycogen becomes important


role of Liver glycogen/ how much we store/ exercise intensity usage

main role to keep constant blood glucose lvl (prevent hypoglycaemia)
As exercise intensity increases more glucose released

@ rest- 60% glucose from liver glycogenolysis

@>75- 90% from liver glucose genolysis


T/F- is 40-50% carbs in diet enough for repeated training days



Classical super compensation model( how is it done and results)

results in high muscle glycogen conc. past norm lvls

-depletion of carbs first, then 3 days very high carbs
allows muscle glycogen to bounce back higher

-only 2 training days tho


moderate super compensation model (how its done and results)

training reduces gradually, carbs raise gradually
-studies found can work for elite athletes in only 1-2 days
-done more
suitable for marathon + triathletes (not explosive athlete)


Lukes study- what is it on, background(what is it important for), and his study +results

Betaine supplementation
past studies found some improvement in performance
is a methyl donor and important for fluid balance

study q- effects on running performance lactate prod

didn’t improve performance during SIT, lactate sig lower but didn’t have an effect on performance


benefits of carb intake hours before exercise

increased carb oxidation + execrated glycogen breakdown during ex

blunting of fatty acid mobilization, + fat oxidation


benifits of carb intake 30-60 mins before

prevents hypoglycaemia (increase plasma glucose + insulin)


factors determining glycemic response during ex.

-stim. effects of insulin +catecholamines on liver glucose output
-magnitude of ongoing absorption


what does carbs during exercise do

maintains blood glycogen + high levels of carb ox
-glycogen sparing
-promotes glycogen synthesis during ex


exogenous carb oxidation- amount of carbs should be eaten, type of carbs that oxidizes at higher rate
and how exercise intensity affects it

amount- consume 70g/h for optimum delivery

type- glucose oxidazes at higher rates then fructose/galactose

exercise intensity- high intensity= more dependence on carbs (more muscle glycogenolysis+ plasma glucose oxidation)


limits to exogenous carb ox

gastric emptying
digestion of carbs/intestinal absorption
glucose uptake


rate of glycogen synthesis after exercise depends on

-availability of glucose
-transcription of glucose into cell
activities of enzymes


name of active/inactive glycogen synthase

I = active
D= inactive


rapid phase of glycogen synthesis post ex. ( what is glycogen synthase doing + other enzymes needed)

when muscle glycogen low= more I form
glucose only formed if substrate (UDP-glucose) available
after ex. abundance of GLUT-4 facilitates uptake of glucose


what happens during slow phase of glycogen synthesis after ex.

dependent on circulating insulin which increases GLUT 4 which increases glucose transport to muscle