Exercise Flashcards
When looking at glucose and insulin levels for people with insulin intolerance who exercised for 7 days vs. those who did not, what do we see?
Lower blood glucose levels and lower insulin levels in the exercising group.
Exercise affect on insulin insensitivity
Your cells will become more insulin sensitive, which is good :)
AMPK catabolism
Important during exercise.
Decreases ATP consumption.
Increases catabolism.
AMP will up regulate the AMPK.
AMPK will increase GLUT4 activity and increase glucose transport to adipose tissue and muscle.
AMPK will increase fatty acid oxidation and glucose uptake
AMPK will inhibit synthetic pathways because they require ATP.
How does epinephrine increase glycolysis in the muscle?
It will phosphorylate glycogen phosphorylase (breaks down glycogen).
The end point of glycogen degradation in the muscle is Glucose-6-phosphate and from there you make fructose-6-phosphate.
Now we accumulate F6P, which is the substrate for PFK1 and PFK2. PFK2 will Inactivate PFK1 and make more Fructose 1,6 bisphosphate and do more glycolysis..Because we have an abundance of fructose-6-phosphate, some of it will form fructose 2,6 bisphosphate, which will up regulate glycolysis even more.
Regulation if beta-oxidation in muscle
ACC-2 inhibits CPT-1 by converting Acetyl CoA to malonyl CoA, which if you remember was important in beta oxidation for bringing the fatty acid into the mitochondria.
As energy levels drop, AMP activates AMP-activated protein kinase (AMP-PK), which phosphorylates and inactivates ACC-2. It also phosphorylates and activates malonyl CoA decarboxylase (MCoADC).
MCoADC converts malonyl CoA to Acetyl CoA, thus relieving the inhibition of malonyl CoA on CPT-1.
Glyceroneogenesis
Essentially an abbreviated version of gluconeogenesis.
Allows the fat cells to make glycerol-3-phosphate, the backbone of lipolysis.
Allows us to get rid of excess fatty acids that were released during a fasting state and repackage them as TAG
Phosphagen system
Creatine phosphate system. Quick burst of energy.
Biological energy systems used by muscle
Phosphagen system
Glycolysis
Oxidative system
How long do each energy system last and when would you use it?
Phosphocreatine - quick bursts like discus
Muscle glycogen - sprinting, so short exercises
oxidative system - Fatty acids, ketone bodies, blood glucose - marathon, long term
As Your exercise session lengthens what changes will you see with regards to percentage of aerobic and anaerobic energy systems being used?
The longer the most aerobic will be used
Type I fibers
Slow twitch
Low glycogen content
High capacity to store O2
High capacity for aerobic metabolism
Type II metabolism
Fast twitch
High glycogen content
More sensitive to fatigue compared to other types
What types of people will have higher fast twitch (II) and slow twitch (I)
I - marathoners, swimmers
II - weight lifters, sprinters
How long does replenishing phosphagen take?
8 min for the Creatine phosphate
- 3-5 just for the ATP
When is muscle glycogen more important? Liver glycogen?
Muscle - moderate intensity exercise
Liver - low intensity but long duration exercise
