Lecture 5 Fats Flashcards
Fatty Acids that are oxidized in the mitochondria of skeletal muscle during exercise are derived from various sources:
Adipose tissue triacylglycerol (TAG) broken down by hormone sensitive lipase
Intramuscular triacylglycerol (IMTG) broken down by hormone sensitive lipase
plasma triacylglycerol broken down by endothelial lipoprotein lipase
Glycerol from TAG goes where?
After TAG is broken down into 3 fatty acids and 1 glycerol, the FA goes to the blood stream where it then is sent to the muscles, and the glycerol goes to the liver to form glucose.
Intramuscular Triacylglycerol (IMTG)
IMTGs are located where? and what happened to IMTGs in trained individuals? What type of muscle fibre have a higher content of IMTG?
adjacent to the mitochondria as lipid droplets
Exercise training increases the number of IMTGs next to the mitochondria. This means the rate at which the body is able to use FA for energy is quicker because its closer to the mitochondria.
Type I have a greater content of IMTGs compared to Type II
What are two essential fatty acids?
Omega-3
Omega-6
Fat is the predominant fuel at ______ and for _______ exercise
As Exercise Intensity Increases (Higher VO2 Max%) what happens to fat oxidation?
rest, light
decreases
Pie charts
25% VO2max = mainly _____
65% VO2max = mainly _____ and _____
85% VO2max = mainly ______ but fat oxidation does not go away completely
Therefore, as exercise INTENSITY increases, fat oxidation decreases and carbohydrate oxidation increases
fats
carbs fats
carbs
T or F
Carbs before exercise decreases fat oxidation by about 30%
T
If you have extra glucose, what can happen?
it can be converted to fatty acids then combines with glycerol to be stored as triaglycerides and can be used for energy when needed
Fat training adaptations
What do well conditioned athletes have?
Good protein status for the athlete is essential as:
Higher glycogen stores improve the ability to metabolize fats without producing ______ resulting in better and linger fate metabolism. Lower glycogen storage reduces efficient fat metabolism and lowers the total ________ _______ from fat
If an athlete can use more fat during high-intensity exercise, they can:
More mitochondria per cell and more oxidative enzymes in each mitochondrion. This enables better and more fat metabolism to satisfy the energy requirement
ability to move fat from storage to working muscle requires the blood protein albumin as it is the primary lipid transporter from storage to working muscles
preserve more carbs to prolong their exercise
T or F
Fasting and exercise is not super beneficial because you don’t have any glycogen for the workout, and so your body will convert FA back to triglycerides and store it back in adipose tissue
T
High-fat low carb diet means:
you will have low-glycogen and you will be more tired during exercise
High fat diets impair high intensity exercise because:
Therefore, high fat diets are not suitable for most sports T or F
performance bouts of high-intensity exercise at intervals during prolonged steady state exercises are impaired by high-fats diets
because fats cannot sustain you at prolonged high-intensity exercise
T
Fat intake During exercise
Recommendations:
Avoid fats during exercise
Absorption is a lot slower than carbohydrates
Ingestion of long-chain triglycerides during exercise is not desirable because they __________gastric emptying
Medium-chain triglycerides are _______ emptied form the stomach and absorbed and oxidized, but the ingestion of larger amounts of MCTs cause _________ _______
Neither of these strategies improve endurance performance so no need to ingest this during exercise
slow
rapidly
gastrointestinal distress
Fat-Intake after exercise:
Normal dietary recommendations for fats (20-35%)
