Nutrition Flashcards
Carbohydrates (Sugars and starches)
Can be metabolized for energy; Blood glucose is maintained within narrow limits by endocrine system
Carbohydrates (dietary fiber)
Cannot be digested or metabolized; provides satiation; reduces transit time in intestine; binds to bile
Why do we start to increase fat utilization as we increase duration of exercise
Usage of aerobic energy systems; run out of glycogen/carbohydrates
What 3 factors impact muscle glycogen level?
- Carbohydrates content of diet
- Prior exercise
- Muscle glycogen super-compensation
How do high carb diets improve endurance performance
They increase muscle glycogen and performance
When are carb diets most important?
In events at high intensity lasting over 1 hour
How does prior exercise effect muscle glycogen levels
Glycogen depletion leads to greater synthesis following exercise
What is muscle glycogen supercompensation
After exhausting exercise, glycogen is depleted in muscles being used. Rest and high-carbohydrate diet results in glycogen overshoot (supercompensation) in those muscles
What is the supercompensation classical method
Follow prolonged strenuous exercise that depleted glycogen stores, go on a high fat/ protein diet for three days while still training (glycogen low as possible). Then start a 90% carb diet for three days with no training
When is the best time to eat before a competition?
Larger meal 2-3 hours before or small snack 5-10 minutes before
What occurs if you consume carbohydrates 30-45 minutes prior to exercise?
A faster rather of muscle glycogen utilization causing a fall in blood glucose during exercise (amount of CHO doesn’t matter)
What caused the blood glucose drop at the start of exercise when eating 30-45 minutes prior
Glucose triggers an Insulin spike right after meal causing a drop in blood glucose
How can you minimize hypoglycemia in a completion
Consume carbohydrates in the last 5 minutes before competition or exercuse to minimize risk of hypoglycemia; avoid high glycemic index carbs
When comparing exhaustive exercise to no exercise, glycogen storage levels will deplete and only return back to baseline levels when consuming carbohydrates during recovery
False
How does carbohydrate intake during exercise improve performance?
Carbohydrates ingestion can maintain plasma glucose even as glycogen is depleted; delays fatigue
How much carbohydrate should you consume during exercise
30-60 grams of carbs per hour during exercise or prior to fatigue
How is glycogen synthesis enhanced after exercise?
There is increased glycogen synthase activity
How much carbohydrate should be consumed immediately after exercise?
1.0-1.5 g/kg within 30 minutes and every 2 hours for 6 hours
How are proteins beneficial after exercise
They reduce carbohydrate need for resynthesizing glycogen after exercise and enhance muscle protein synthesis
What are the 6 benefits of fat
- Fuel for energy
- Hormone synthesis
- Absorption of fat-soluble vitamins
- Cell membrane structure
- Insulation
- Protection of vital organs
What are the consequences of fat loading?
There is a reduction of glycogen stores when fat oxidation is increased during exercise
Why aren’t proteins a major source of energy
They contain nine essential amino acids but cannot be synthesized in the body
How are the daily protein intake requirements?
0.8 g/kg per day; higher in athletes
When would you use protein for energy?
Starvation; long duration/higher intensity (BAD!)
